1.

To what extent is legislation of a Member State concerning nationality, which provides that the nationals of that Member State lose their nationality when they voluntarily acquire foreign nationality, unless they have requested and obtained permission to retain their nationality before that acquisition, compliant with Article 20 TFEU?

2.

That, in essence, is the legal issue which arises in the present cases and which forms the subject matter of two questions referred for a preliminary ruling by the Verwaltungsgericht Düsseldorf (Administrative Court, Düsseldorf, Germany) in proceedings concerning the loss of German nationality.

3.

In the present case, the Court is called on once again to consider whether national rules on loss of nationality comply with EU law. The present cases arise against the background of the case-law deriving from the judgments in Rottmann, ( 2 )Tjebbes and Others, ( 3 )Wiener Landesregierung (Revocation of an assurance of naturalisation) ( 4 ) and Udlændinge- og Integrationsministeriet (Loss of Danish nationality). ( 5 )

4.

Article 20(1) TFEU establishes citizenship of the European Union and provides that ‘every person holding the nationality of a Member State’ is a citizen of the European Union.

5.

The Staatsangehörigkeitsgesetz (Law on nationality) ( 6 ) (‘the StAG’), which has been in force since 1 January 2000 and applies to the main proceedings, provides in Paragraph 25:

‘(1)   A German shall lose his or her nationality upon acquisition of foreign nationality if such acquisition occurs upon application by him or her or upon application by his or her legal representative, whereas the represented person shall suffer such loss only if the conditions for application for withdrawal under Paragraph 19 are met. The loss in accordance with the first sentence shall not take effect if a German acquires the nationality of another Member State of the European Union, Switzerland or a State with which the Federal Republic of Germany has concluded a treaty under international law pursuant to Paragraph 12(3).

(2)   Nationality shall not be lost by any person who, prior to acquisition of foreign nationality upon application by him or her, has received the written permit from the competent authority to retain his or her nationality. … In the decision on an application pursuant to the first sentence, the public and private interests shall be weighed up. In the case of an applicant who is habitually resident abroad, special consideration shall be given to whether he or she is able to furnish credible evidence of continuing ties with Germany.’

6.

The facts of the main proceedings, as they appear from the orders for reference, may be summarised as follows.

7.

The applicant in the main proceedings relating to Case C‑684/22, S.Ö., was born in Türkiye in 1966 and entered Germany in 1990. He is married and a father to three children. He acquired German nationality by naturalisation on R10 May 1999, and his Turkish nationality was withdrawn on 13 September 1999.

8.

On 25 May 2018, when applying for a travel document for his son, S.Ö. disclosed that he had reacquired Turkish nationality on 12 November 1999. In that regard, he submitted a certificate dated 27 February 2019 issued by the Turkish Ministry of the Interior and an extract from the civil register dated 6 November 2018, according to which he had applied for reacquisition of Turkish nationality on 13 September 1999 and reacquired it by order of the Turkish Council of Ministers of 12 November 1999.

9.

The German authorities indicated that there were reasonable doubts as to whether S.Ö.’s son held German nationality, and on 25 April 2019, S.Ö. applied to the naturalisation authority for the city of S. to issue him with a certificate of nationality, in order to establish that he continued to hold German nationality. At a later date, S.Ö moved to the area falling within the competence of the city of Duisburg (Germany).

10.

The applicants in the main proceedings relating to Case C‑685/22 are a married couple, M.Ö. and N.Ö., who were born in 1959 and 1970, respectively, and entered Germany in 1974. They acquired German nationality by naturalisation on 27 August 1999, and their Turkish nationality was withdrawn on 2 September 1999.

11.

On 1 September 2005, during an interview with the authorities of the city of Wuppertal (Germany), they indicated that they had reacquired Turkish nationality on 24 November 2000. In that regard, they produced a certificate dated 31 August 2005 issued by the Turkish Consulate General in E., according to which they had applied for reacquisition of Turkish nationality on 2 September 1999 and reacquired it by order of the Council of Ministers of 24 November 2000. By letter of 1 December 2016, the applicants submitted to the city of Wuppertal an extract from the Turkish civil register, according to which reacquisition of Turkish nationality had already occurred on the basis of an order of the Council of Ministers of 1 November 1999.

12.

In August 2020, the city of Wuppertal informed M.Ö. and N.Ö. that it was sufficiently likely that there had been manipulation of the date in the extract from the Turkish civil register, and that the extract could therefore have no probative value going beyond reacquisition of Turkish nationality.

13.

The applicants in the main proceedings relating to Case C‑686/22 are a married couple, M.S. and S.S, who were born in 1965 and 1971 and respectively entered Germany in 1981 and 1989. They acquired German nationality by naturalisation on 10 June 1999, and their Turkish nationality was subsequently withdrawn.

14.

When they applied for withdrawal of Turkish nationality, in order to meet one of the requirements for naturalisation as German citizens, M.S. and S.S. also applied to the Turkish authorities for reacquisition of Turkish nationality, once they had been granted German nationality. They were advised, in accordance with German law at the time, that they could reacquire Turkish nationality without thereby losing German nationality. In that regard, they submitted an extract from the Turkish civil register, according to which they reacquired Turkish nationality on 9 August 1999 on the basis of an order of the Council of Ministers.

15.

On 19 December 2017, M.S. and S.S. applied to the city of Krefeld (Germany) for a declaration that they held German nationality. Although the city of Krefeld did issue them with a certificate of nationality on 24 August 2018, it reinstituted the procedure on the ground that there was no number for the order of the Council of Ministers in the Turkish civil register.

16.

By orders of the administrative police, ( 7 ) the defendants in the main proceedings declared, in accordance with Paragraph 30(1) of the StAG, that S.Ö., M.Ö., N.Ö., M.S. and S.S. (‘the applicants in the main proceedings’) were no longer German nationals. ( 8 ) They determined that the reacquisition of Turkish nationality had occurred after 1 January 2000 and, in accordance with point 2 of Paragraph 17(1) and the first sentence of Paragraph 25(1) of the StAG, resulted in an automatic loss of German nationality. It would have been otherwise if the reacquisition of Turkish nationality had occurred before 31 December 1999, since the first sentence of Paragraph 25(1) of the Reichs- und Staatsangehörigkeitsgesetz (Law on imperial citizenship and nationality, ‘the RuStAG’) of 22 July 1913, ( 9 ) which had previously been applicable, provided that loss of German nationality took effect only for Germans residing abroad. However, the applicants in the main proceedings had not proved reacquisition of Turkish nationality prior to 1 January 2000.

17.

The applicants in the main proceedings then brought an action against those orders of the administrative police before the Verwaltungsgericht Düsseldorf (Administrative Court, Düsseldorf), which is the referring court.

18.

In its three requests for a preliminary ruling, the referring court states that Paragraph 25 of the StAG, which has been in force since 1 January 2000, is applicable to the applicants in the main proceedings because they reacquired Turkish nationality after the amended legislation entered into force. That court states that the extracts from the civil register produced by the applicants to demonstrate that that is not the case have no probative value. It also observes that the applicants in the main proceedings did not apply for a permit to retain German nationality, as referred to in the first sentence of Paragraph 25(2) of the StAG, before reacquiring Turkish nationality.

19.

In that regard, the referring court states that, according to national case-law, the first sentence of Paragraph 25(1) of the StAG is consistent with EU law because the person concerned is able to apply for a permit to retain German nationality under the first sentence of Paragraph 25(2) of the StAG; as part of that procedure, an individual examination of the consequences of the loss for the situation of the person concerned is expressly required.

20.

The referring court nevertheless has doubts as to whether the first sentence of Paragraph 25(1) of the StAG is in fact consistent with EU law. It observes that, where the procedure for obtaining advance permission to retain nationality provided for in Paragraph 25(2) of the StAG (‘the advance permission procedure’) is not initiated, the effect of that provision is that loss of nationality – and thus, for persons who do not hold the nationality of another Member State, of citizenship of the European Union – occurs automatically, without any individual examination. The referring court states that German law makes no provision for an ancillary examination of the consequences of loss of German nationality after it has been lost. In such circumstances, the only way for the persons concerned to recover German nationality – without retroactive effect – would be to make another application for naturalisation.

21.

Furthermore, while noting that, in accordance with the wording of Paragraph 25(2) of the StAG, an application for permission to retain nationality provides an opportunity for account to be taken of the requirements of EU law, as interpreted by the Court, since it is those requirements which are to be considered, in the decision on such an application, in weighing up the public and private interests, the referring court states that, in practice, the consequences of loss of EU citizenship are not examined by the administrative authorities or in national case-law. Permission to retain nationality is granted only where there is a special interest in acquisition of a foreign nationality while retaining German nationality.

22.

In those circumstances, the Verwaltungsgericht Düsseldorf (Administrative Court, Düsseldorf), by decisions of 3 November 2022 which reached the Court on 8 November 2022, decided to stay the main proceedings relating to the three cases and refer the following questions to the Court of Justice for a preliminary ruling:

23.

By decision of 7 December 2022, Cases C‑684/22 to C‑686/22 were joined for the purposes of the written and oral parts of the procedure, and of the judgment.

24.

Written observations were submitted, in Case C‑686/22, by the applicants in the main proceedings, the city of Krefeld, the German and Estonian Governments and the European Commission and, in Cases C‑684/22 and C‑685/22, by the same governments and by the Commission. The Court decided not to hold a hearing in the present cases.

25.

By the two questions before the Court on these references for a preliminary ruling, which should be dealt with together, the referring court asks, in essence, whether Article 20 TFUE is to be interpreted as precluding legislation of a Member State providing that its nationals, in the event of voluntary acquisition of the nationality of a third country, automatically lose the nationality of that Member State, which, for persons who are not also nationals of another Member State, entails the loss of their status as EU citizens and of the rights attaching to that status, unless the persons concerned obtain permission to retain that nationality before acquiring the nationality of the third country, the competent national authorities carrying out, as part of the examination of the application for such permission, an individual examination of the situation of the persons concerned, in which the public and private interests in the nationality of that Member State being retained are weighed up.

26.

With a view to proposing a useful answer to that question, it is appropriate, as a preliminary step, to set out some facts and matters which appear from the orders for reference to be common to all three matters.

27.

In the first place, as regards the situation of the applicants in the main proceedings, the referring court explains that they entered Germany in the 1970s, 1980s or 1990s, and have been resident there ever since. In 1999, they acquired German nationality by naturalisation, and as part of that process they renounced their Turkish nationality, which was subsequently withdrawn. As the referring court states, the applicants in the main proceedings, having been advised – correctly, having regard to the German legislation then in force – that they could reacquire Turkish nationality without losing their German nationality, voluntarily applied to reacquire Turkish nationality as soon as it was withdrawn. Several years later, the competent authorities noted that the applicants in the main proceedings had reacquired Turkish nationality after making an application to that end and that, consequently, in accordance with the German legislation in force since 1 January 2000, they had automatically lost German nationality, and with it their status as EU citizens. ( 10 ) Moreover, given that, in accordance with that legislation, the applicants in the main proceedings had not applied for – and obtained – permission from the competent authorities to retain German nationality before they reacquired Turkish nationality, they did not have the benefit of the individual examination which is provided for in connection with such applications, involving a weighing-up of the public and private interests in German nationality being retained.

28.

In the second place, as regards the legislation at issue, the referring court states, first of all, that Paragraph 25(1) of the StAG, which has been in force since 1 January 2000, provides that a German national loses his or her nationality upon acquisition of foreign nationality if such acquisition occurs upon application by him or her. However, under Paragraph 25(2) of the StAG, that person can retain his or her nationality if, before acquiring the foreign nationality, he or she applies for and obtains written permission from the competent authority. That subparagraph also provides that, in the decision on such an application, the public and private interests are to be weighed up.

29.

The referring court goes on to explain that the applicants in the main proceedings acquired German nationality by naturalisation – and applied to reacquire Turkish nationality – before1 January 2000, the date on which Paragraph 25 of the StAG entered into force. ( 11 ) It states that that provision applies to them because they reacquired Turkish nationality after that date, explaining that the documents produced to demonstrate that that is not the case have no probative value. ( 12 )

30.

Lastly, the referring court states that the applicants in the main proceedings did not apply for – and thus obtain – authorisation to retain their nationality before reacquiring Turkish nationality, as provided for by Paragraph 25(2) of the StAG. Consequently, the loss of their German nationality, and with it their status as EU citizens, occurred automatically, and they did not have the benefit of an individual examination of their circumstances.

31.

That is the legal issue which lies at the heart of the present cases and which I will deal with in this Opinion. I will address the broad outline of the case-law of the Court on the loss of EU citizenship, and the principles which are to be distilled from that case-law (section A) and which are applicable in the present case (section B).

32.

In my Opinion in Udlændinge- og Integrationsministeriet, I stated that the common thread running through the case-law I analysed, resulting from the judgments in Rottmann, Tjebbes and Others and Wiener Landesregierung, is essentially composed of two case-law principles. ( 13 )

33.

Under the first principle, while it is for each Member State to define the ‘conditions for the acquisition and loss of nationality’, their power to do so must be exercised in a manner compatible with EU law. ( 14 ) In relation to that principle, which was established in the judgment inMicheletti and Others, ( 15 ) then clarified and confirmed in the judgment in Rottmann, ( 16 ) it is necessary to distinguish the existence of that exclusive power of the Member States from its exercise with due regard to the EU legal order.

34.

Moreover, that power has never been questioned by the Court and ‘the acquisition and loss of nationality (and, consequently, of Union citizenship) are [not] in themselves governed by [EU] law, but the conditions for the acquisition and loss of nationality must be compatible with the [EU legal] rules and respect the rights of the European citizen’. ( 17 ) Thus, the fact that a matter falls within the competence of the Member States does not alter the fact that, in situations covered by EU law, the national rules concerned must have due regard to the latter. ( 18 ) Article 20 TFEU cannot be rendered redundant and, therefore, the rights which it confers on EU citizens cannot be infringed by the adoption of national legislation which does not comply with EU law and, in particular, does not observe the principles deriving from the case-law of the Court in this field. ( 19 )

35.

The second principle, which was established by the Court in the judgment in Rottmann, ( 20 ) then confirmed in its subsequent case-law, is that, in respect of citizens of the European Union, the exercise of that competence, in so far as it affects the rights conferred and protected by the EU legal order, is amenable to judicial review carried out in the light of EU law and, in particular, in the light of the principle of proportionality. ( 21 ) In other words, national legislation providing for the loss of EU citizenship can be compliant with EU law only if it is based on legitimate grounds and complies with that principle. It is also apparent from the case-law that, in the context of compliance with the principle of proportionality, there are several matters to be taken into consideration. First of all, the obligation to conduct an individual examination of the consequences of the loss of EU citizenship for the person concerned and, if relevant, the members of his or her family, with regard to the loss of the rights enjoyed by every citizen of the European Union, ( 22 ) secondly, the requirement for those consequences to be consistent with the fundamental rights guaranteed by the Charter of Fundamental Rights of the European Union (‘the Charter’) ( 23 ) and, lastly, in cases where the loss of nationality arises by operation of law and entails the loss of EU citizenship, the obligation to examine, as an ancillary issue, the consequences of the loss of that nationality and, where appropriate, to enable the person concerned to retain his or her nationality or to recover it ex tunc. ( 24 )

36.

In relation to that last matter in particular, it seems to me that the judgment in Udlændinge- og Integrationsministeriet is especially relevant, because it was in that judgment that the Court ruled for the first time on the time limits for making an application to retain or recover nationality of a Member State.

37.

In the case which gave rise to the judgment in Udlændinge- og Integrationsministeriet, ( 25 ) a Danish court wished to know whether the national legislation on nationality was compliant with Article 20 TFEU, read in conjunction with Article 7 of the Charter.

38.

In its judgment, the Court confirmed its earlier case-law. It thus pointed out that, where the loss of the nationality of a Member State arises by operation of law at a given age and entails the loss of citizenship of the European Union and the rights attaching thereto, the competent national authorities and courts must be in a position to examine the consequences of the loss of that nationality from the point of view of EU law and, where appropriate, to enable that person to retain his or her nationality or to recover it ex tunc. ( 26 )

39.

In particular, as regards the time limit for making an application for such an examination for the purposes of retaining or recovering nationality, the Court stated that in the absence of a specific time limit laid down by EU law for that purpose, it is for each Member State to lay down procedural rules to ensure the safeguarding of rights which individuals derive from EU law, provided that those rules comply, inter alia, with the principle of effectiveness in that they do not make it in practice impossible or excessively difficult to exercise rights conferred by EU law. The Member States may, in that regard, require, on the basis of the principle of legal certainty, that such an application be submitted to the competent authorities within a reasonable period. ( 27 )

40.

However, the Court also stated that, in the light of the serious consequences arising from the loss of the nationality of a Member State, where that loss entails the loss of citizenship of the European Union, for the effective exercise of the rights which such citizens derive from Article 20 TFEU, national rules or practices liable to have the effect of preventing the person concerned from seeking an examination of the proportionality of those consequences from the point of view of EU law cannot be regarded as compatible with the principle of effectiveness. The Court therefore declared that where that person has not been duly informed of the right to request such an examination and of the deadline for lodging such a request, his or her request cannot be held to be inadmissible on the ground that that deadline has expired. ( 28 )

41.

It is thus in the light of those case-law principles that the loss of nationality provided for by the legislation at issue in the main proceedings, entailing the loss of EU citizenship, must be examined.

42.

I would point out at the outset that the Court has repeatedly held that Article 20 TFEU confers on every individual who is a national of a Member State citizenship of the European Union, which is intended to be the fundamental status of nationals of the Member States. ( 29 ) That means, on the one hand, that possession of the nationality of a Member State is a precondition for the enjoyment of the status of citizen of the European Union, to which all the duties and rights provided for by the FEU Treaty are attached, ( 30 ) and, on the other hand, that in circumstances such as those of the main proceedings, the loss of that status constitutes the connection with EU law.

43.

In the present case, the referring court observes that the applicants in the main proceedings reacquired Turkish nationality after Paragraph 25 of the StAG had entered into force, with the consequence that they automatically lost their German nationality, and with it their status as citizens of the European Union. ( 31 )

44.

It is thus clear that loss of the nationality of a Member State on the part of citizens of the European Union who, like the applicants in the main proceedings, are nationals of one Member State only and who, by losing that nationality, are faced with losing the status conferred by Article 20 TFEU and the rights attaching thereto, falls, by reason of its nature and its consequences, within the ambit of EU law. ( 32 ) Thus, according to the settled case-law of the Court, the Member States must, in exercising their competence in the field of nationality, comply with EU law and, in particular, the principle of proportionality. ( 33 )

45.

I would note that the Court has already held that it is legitimate for a Member State to wish to protect the special relationship of solidarity and good faith between it and its nationals and also the reciprocity of rights and duties, which form the bedrock of the bond of nationality. ( 34 ) It has held that it is also legitimate for a Member State, when exercising its competence to lay down the conditions for acquisition and loss of nationality, to take the view that nationality is the expression of a genuine link between it and its nationals, and therefore to prescribe that the absence, or the loss, of any such genuine link entails the loss of nationality. ( 35 )

46.

In the present case, under Paragraph 25(1) of the StAG, German nationals lose their nationality by operation of law where they voluntarily acquire the nationality of a third country, unless they obtain permission to retain their nationality before acquiring the foreign nationality.

47.

I note that the referring court does not explain, beyond the mention, in its summary of the legal framework, of Article 7(1)(a) of the European Convention on Nationality, ( 36 ) what public interest ground or grounds are pursued by Paragraph 25(1) of the StAG. However, given that that provision can only be compliant with EU law if it pursues a legitimate public interest ground, it should be examined in the light of the observations of the German government.

48.

As the city of Krefeld and the German Government have indicated, and as is apparent from the statement of reasons for the Law reforming the law on nationality of 15 July 1999, Paragraph 25 of the StAG is intended, inter alia, to prevent multiple nationality. ( 37 ) The German Government states, in addition, that the case-law of the Bundesverfassungsgericht (Federal Constitutional Court, Germany) holds that the legislature’s decision to obstruct unlimited multiplicity of nationalities is beyond criticism. ( 38 )

49.

In that regard, there is no doubt that a system such as that provided for by Paragraph 25 of the StAG falls within the exercise of the power of the Member States to define the conditions of acquisition and loss of nationality and that, in exercise of that power, it is legitimate for a Member State, such as the Federal Republic of Germany, to take the view that the consequences of holding multiple nationalities should be avoided in certain cases. ( 39 )

50.

The legitimacy, in principle, of that objective is corroborated by Article 7(1)(a) of the European Convention on Nationality, under which a State Party may not provide in its internal law for the loss of its nationality ex lege or at the initiative of the State Party except, inter alia, in the case of voluntary acquisition of another nationality. ( 40 ) According to the explanatory report on that convention, whether persons who voluntarily acquire another nationality are allowed to retain their previous nationality will depend upon the individual situation in each State. ( 41 )

51.

I would observe, in that regard, that EU law does not preclude a Member State from providing for the issue of whether or not there is a genuine link with that State to be assessed by applying a test, such as that set out in Paragraph 25(1) of the StAG, based on voluntary acquisition of the nationality of a third country by the person concerned; nor, against a legislative background in which multiple nationality is, in principle, to be avoided, does it preclude that Member State from requiring the person concerned to follow a specific procedure, such as that set out in Paragraph 25(2) of the StAG, where he or she wishes to retain German nationality.

52.

In those circumstances, I consider, like the German and Estonian Governments and the Commission, that, in the circumstances of the main proceedings, EU law does not, in principle, preclude a Member State, in the situations contemplated by Paragraph 25 of the StAG, from providing, on public interest grounds, for automatic loss of nationality where its nationals voluntarily acquire the nationality of a third country, even where that loss entails, for the person concerned, the loss of his or her EU citizenship.

53.

That having been said, in order for national legislation such as that at issue in the main proceedings, which provides for the loss of EU citizenship, to be compliant with EU law, it must not only seek to pursue legitimate public interest grounds, but also comply with the principle of proportionality.

54.

While, as I have just set out, EU law does not, in principle, preclude the legislation at issue in the main proceedings, I would nevertheless observe that it is apparent from settled case-law that, having regard to the importance which primary EU law attaches to the status of citizen of the European Union, which constitutes the fundamental status of nationals of the Member States, the competent national authorities and national courts must determine whether the loss of the nationality of the Member State concerned, when it entails the loss of citizenship of the European Union and the rights attaching thereto, has due regard to the principle of proportionality so far as concerns the consequences of that loss for the situation of the person concerned and, if relevant, for that of the members of his or her family, from the point of view of EU law. ( 42 )

55.

Furthermore, it is apparent from the same case-law that the loss of the nationality of a Member State by operation of law would be inconsistent with the principle of proportionality if the relevant national rules did not permit at any time an individual examination of the consequences of that loss for the persons concerned from the point of view of EU law. ( 43 )

56.

In the present case, I would observe that, in accordance with Paragraph 25(2) of the StAG, German nationals wishing to acquire, voluntarily, the nationality of a third country may make an application to retain their German nationality under the advance permission procedure which provides that, in the decision on an application for permission, the public and private interests are to be weighed up.

57.

The question arises, as a preliminary matter, of whether the examination of proportionality required by EU law can be conducted by the competent authorities only at a specific point in time – namely, in this case, before the automatic loss of nationality and thus of EU citizenship, within the framework of the advance permission procedure.

58.

That is not a difficult question to answer. In the light of the case-law referred to in point 55 of this Opinion, it is, in principle, possible for a Member State, such as the Federal Republic of Germany, to provide that the examination of proportionality is to be conducted within the specific framework of an advance permission procedure, such as that provided for by Paragraph 25(2) of the StAG. However, as is apparent from that same case-law, in order to be compatible with EU law, that provision must guarantee the right to an individual examination of the proportionality of the consequences, for the persons concerned and, if relevant, for the members of their family, of the loss of German nationality, from the point of view of EU law.

59.

The referring court is not sure that that requirement is met in the present case. I confess that I also find it difficult to understand how that procedure relates to the principle of proportionality and, more specifically, how its application guarantees the right to an individual examination required by EU law. Accordingly, in what follows I will analyse, first, the procedural arrangements provided for by Paragraph 25(2) of the StAG and, secondly, the substantive scope of the examination of proportionality for which it provides.

60.

It will be recalled that, under Paragraph 25(2) of the StAG, German nationality can be retained if, prior to acquiring the nationality of a third country, the person concerned has obtained, from the competent authority, written permission to retain his or her nationality.

61.

The question therefore arises of whether, within the framework of the advance permission procedure, the time limits within which the application must be made – and the permission obtained – are compatible with EU law. If they are to be compatible, those time limits must not prevent the persons concerned from exercising the rights attaching to their EU citizenship in an effective manner.

62.

With regard, in the first place, to the time limit applicable to the making of the application for permission, the Court has held that the Member States may require, on the basis of the principle of legal certainty, that an application for the maintenance or recovery of nationality be submitted to the competent authorities within a reasonable period. ( 44 )

63.

It follows, in my opinion, that a requirement for an application for permission to retain the nationality of a Member State to be made before the acquisition of the nationality of a third country, as imposed by Paragraph 25(2) of the StAG, appears to meet the criterion of a reasonable period within the meaning of that case-law, provided that, in principle, it does not prevent the nationals concerned from exercising their right to an individual examination by the competent authorities of the proportionality of the consequences of the loss of nationality, from the point of view of EU law.

64.

That having been said, I should point out that it is apparent on reading the orders for reference, the observations of the applicants in the main proceedings relating to case C‑686/22, and the observations of the Commission, that there is uncertainty as to whether the applicants in the main proceedings were duly informed of the consequences of recovering Turkish nationality on their situation and that of their families in the specific legislative context of the reform of the RuStAG.

65.

The applicants in the main proceedings state that, when they made their application to recover Turkish nationality, the legislation that was in force permitted them to recover that nationality. There was therefore no reason to make the application for advance permission. They also state that the change in the law was not clearly explained or brought to their attention. It was after they had made their application to recover Turkish nationality that the RuStAG was amended and the possibility for German nationals resident in national territory to obtain dual nationality was withdrawn and limited. I have some remarks to make about those observations.

66.

On the one hand, in the light of the case-law, ( 45 ) it seems at least plausible, having regard to the dates on which Turkish nationality was recovered, as indicated by the referring court, under the system instituted by Paragraph 25 of the StAG, that the applicants in the main proceedings did not have effective access to an individual examination of their situation from the point of view of EU law.

67.

As the Commission has rightly stated, it must be borne in mind that, first, the law in force up to 31 December 1999neither required nor, where applicable, permitted an application to be made to retain German nationality in the event of Turkish nationality being recovered by a German national resident in national territory. Secondly, as the referring court has also pointed out, during the period between the entry into force of the amended version, on 1 January 2000, and the recovery of Turkish nationality, no possibility of initiating and effectively conducting such a procedure was open to, inter alia, persons who had recovered Turkish nationality in early 2000, such as the applicants. ( 46 ) Thus, some of the persons concerned were deprived, prior to the loss of German nationality, of the possibility of effective access to the examination of their individual situation required by EU law, this being a matter for the referring court to verify. ( 47 )

68.

On the other hand, in the light of that same case-law, it is possible in my opinion, having regard to the serious consequences of losing the nationality of a Member State, to require of national authorities and courts that the persons concerned must be duly informed, first, of the fact that if they were to acquire or recover the nationality of a third country, that would entail the loss of German nationality, and, secondly, of the advance permission procedure which enables an application to retain that nationality to be made, and of the time limit for making such an application.

69.

In the present case, it is for the referring court to determine, amongst other things, having regard to the fact that the applicants in the main proceedings were required to renounce their Turkish nationality in order to acquire German nationality during a period of legislative change, whether they can be considered to have been duly informed. ( 48 )

70.

With regard, in the second place, to the time limit for obtaining permission to retain German nationality, laid down in Paragraph 25(2) of the StAG, I must observe that, under that provision, the moment when the nationality of a third country is obtained marks the expiry of the time limit not only for making the application to retain German nationality, but also for obtaining such permission. Consequently, if such an application for permission is yet to be processed by the competent German authorities on the date when the authorities of the third country issue their decision, it can no longer be examined, which entails the loss of EU citizenship without the persons concerned having had the possibility of effective access to the examination of proportionality required by EU law. The loss of EU citizenship depends, in practice, on a number of factors such as how quickly the competent German authorities conduct the weighing-up of public and private interests and how quickly the application for acquisition of nationality is processed by the authorities of the third country. That having been said, I must point out that the provision at issue does not require the person concerned to make an application to acquire the nationality of a third country at the same time as making an application for permission to retain German nationality. Consequently, in principle, the problem should not arise in so far as the person concerned ought to wait for the German authorities’ decision on permission to retain nationality before making an application to acquire the nationality of a third country.

71.

Furthermore, in so far as the applicants in the main proceedings thought they could retain both German and Turkish nationality, as German nationals resident in Germany were permitted to do under Paragraph 25 of the RuStAG (which was applicable until 31 December 1999), I share the Commission’s view that it would have been ‘appropriate’ to enact transitional provisions to that effect. Such transitional provisions would have enabled persons who had made their application to recover Turkish nationality under the law in force prior to 1 January 2000, but who obtained Turkish nationality after that date, to make effective use of the advance permission procedure provided for by Paragraph 25 StAG. Having regard to the serious consequences that the loss of EU citizenship has for the persons concerned, the lack of any such transitional provisions is, in my view, incompatible with the principle of effectiveness.

72.

Accordingly, having regard to the serious consequences of losing German nationality and, with it, the status of the applicants in the main proceedings as citizens of the European Union, both the application in the present case of the procedural arrangements, such as the time limits laid down by Paragraph 25(2) of the StAG, and the lack of any such transitional provisions seem to me to be incompatible with the principle of effectiveness, in so far as those arrangements or their absence fetter the applicants’ right to obtain an examination of proportionality.

73.

Contrary to what is stated by the city of Krefeld and the German Government, the referring court states that in practice, despite the wording of Paragraph 25(2) of the StAG, where an application for advance permission to retain German nationality is rejected by the competent authorities, no individual examination of the proportionality of the consequences of losing German nationality, from the point of view of EU law, is carried out either by those authorities or by the national courts.

74.

In the first place, I would observe that if, after the referring court has carried out the necessary verifications, that proves to be the case, the mere fact that such an examination is a formal or theoretical part of the advance permission procedure is not sufficient – if, in practice, the examination is not carried out – to ensure that that procedure is compatible with Article 20 TFEU. In that case, it is apparent from settled case-law of the Court ( 49 ) that the referring court must be in a position to require the national authorities to carry out that examination or to examine for itself the consequences of the loss of German nationality for the persons concerned and, where appropriate, to have them recover that nationality ex tunc. ( 50 )

75.

That having been said, the German Government submits, in that regard, that Paragraph 25(2) of the StAG enables a full examination of the legal situation of the person concerned to be made and that the fact that regard is had not only to the public interest in German nationality being retained, but also to the private interest, necessarily means that the interest in retaining EU citizenship is taken into account. If the referring court were to consider that the competent national authorities do conduct the individual examination of the consequences of loss of EU citizenship required by EU law, as indicated by the German Government, it would also have to establish the date from which such examinations have been carried out. If it were to find that such examinations have only been carried out since the date of delivery of the judgment in Tjebbes and Others, I must reiterate that any person who lost German nationality by operation of law prior to that date, under Paragraph 25(1) of the StAG, must be able to obtain such an examination and, where appropriate, recover German nationality ex tunc in the context of an application for a travel document or any other document showing his or her nationality, and more generally, in the context of proceedings for a declaration of nationality. ( 51 )

76.

In the second place, it is apparent from the orders for reference that the applicants in the main proceedings have built a family and professional life in Germany. As German nationals, they were able to exercise their freedom of movement and residence in other Member States.

77.

In that regard, I would point out at the outset that, within the scope of application of EU law, every EU citizen is guaranteed the same level of protection of his or her fundamental freedoms, in particular, his or her right to a family life.

78.

In particular, as regards that right, it is apparent from well-established case-law that, first, the examination of proportionality must include an individual assessment of the situation of the person concerned and that of his or her family in order to determine whether the consequences of losing the nationality of the Member State concerned, when it entails the loss of his or her citizenship of the European Union, might, with regard to the objective pursued by the national legislature, disproportionately affect the normal development of his or her family and professional life from the point of view of EU law. ( 52 ) Secondly, as part of that examination of proportionality, it is, in particular, for the competent national authorities and, where appropriate, for the national courts to ensure that the loss of nationality is consistent with the fundamental rights guaranteed by the Charter, the observance of which the Court ensures, and specifically the right to respect for family life as stated in Article 7 of the Charter. Furthermore, that article must be read, where applicable, in conjunction with the obligation to take into consideration the child’s best interests, recognised in Article 24(2) of the Charter. ( 53 )

79.

In the third place, a question which is important to the outcome of the disputes in the main proceedings arises at this stage: what is the relevant date to be taken into account by the competent authorities for the purposes of the examination of proportionality? It could be argued that, as the Court held in the judgment in Udlændinge- og Integrationsministeriet, that date corresponds to the day on which the person concerned obtained or recovered the nationality of a third country, since, in the present case, in accordance with Paragraph 25(2) of the StAG, that date forms an integral part of the legitimate criteria which that Member State has determined, and on which the retention or loss of nationality depends.

80.

It is quite certain however that, in contrast to the situation in the case which gave rise to the judgment in Udlændinge- og Integrationsministeriet, ( 54 ) in the present case, the answer to that question cannot stop there and must take account of an important factor, namely that the applicants in the main proceedings were not in any circumstances in a position to initiate the procedure for advance permission to retain their German nationality, as Paragraph 25(2) of the StAG had not yet entered into force on the date when they made their applications to recover Turkish nationality. It was thus impossible – both procedurally and substantively – for the applicants in the main proceedings to make an application for advance permission. Since a time limit for applying to retain German nationality had yet to be prescribed, it could not expire, the result being that the persons concerned did not have effective access to an individual examination of their situation from the point of view of EU law. ( 55 )

81.

In the fourth place, and lastly, it seems to me that there is one more factor which must be considered. I note that the referring court states that German law makes no provision for an ancillary examination of the consequences of loss of German nationality after it has been lost. In such circumstances, the only way for the persons concerned to recover German nationality – without retroactive effect – would be to make another application for naturalisation. ( 56 )

82.

That possibility of recovering nationality, given that it entails that the person concerned is deprived, for a certain period, of the possibility of enjoying all the rights conferred by citizenship of the European Union, without it being possible for those rights to be restored during that period, is not compatible with the well-established case-law of the Court. According to that case-law, the fact that national law does not offer the possibility, under conditions which are consistent with EU law, to obtain from the national authorities and, potentially, from the national courts, an examination of the proportionality of the consequences of the loss of the nationality of the Member State concerned from the point of view of EU law and which may, where appropriate, lead to the recovery ex tunc of that nationality, cannot be compensated for by the possibility of naturalisation, regardless of the conditions – possibly favourable – under which that naturalisation may be obtained. To accept that the position is otherwise would be tantamount to accepting that a person could be deprived, even for a limited period, of the possibility of enjoying all the rights conferred on him or her by virtue of his or her citizenship of the European Union, without it being possible for those rights to be restored for that period. ( 57 )

83.

In the light of the above considerations, I propose that the Court should answer the questions referred for a preliminary ruling by the Verwaltungsgericht Düsseldorf (Administrative Court, Düsseldorf, Germany) as follows:

Article 20 TFEU, read in the light of Article 7 of the Charter of Fundamental Rights of the European Union, is to be interpreted as meaning that it does not preclude legislation of a Member State providing that its nationals, in the event of voluntary acquisition of the nationality of a third country, lose the nationality of that Member State by operation of law, which entails, for those who are not also nationals of another Member State, the loss of their EU citizenship and of the rights attaching thereto, unless they obtain permission to retain that nationality before acquiring the nationality of the third country, provided that the persons concerned have effective access, subject to a reasonable time limit, to a procedure for retaining nationality which enables the competent authorities to examine the proportionality of the consequences of the loss of that nationality from the point of view of EU law and, where appropriate, to allow that nationality to be retained or recovered ex tunc. Such a time limit cannot begin to run until those authorities have duly informed the persons concerned of the fact that the potential acquisition or recovery of the nationality of a third country entails the loss of nationality and of the possibility of initiating the advance permission procedure enabling an application to retain that nationality to be made, and also of their right to apply, subject to that time limit, for the retention or recovery of that nationality. Otherwise, those authorities must be in a position to conduct such an examination, as an ancillary matter, where an application is made, by those persons, for a travel document or any other document showing their nationality, or, where applicable, in proceedings for a declaration of the loss of nationality.