1.

Must Article 135(1)(i) of Council Directive 2006/112/EC of 28 November 2006 on the common system of value added tax and the principle of neutrality be interpreted as precluding a Member State from using different treatment for online lotteries offered by Loterie Nationale [(the Belgian national lottery)], a public establishment, which are exempt from value added tax, and other online games of chance offered by private operators, which are subject to value added tax, assuming that they are similar supplies?

2.

In answering the previous question, in order to determine whether there are two similar categories which are in competition with each other and which require the same treatment for the purposes of value added tax, or whether there are separate categories which allow for different treatment, must the national court consider only whether or not the two forms of games are in competition with each other from the point of view of the average consumer, in the sense that services are similar where they have similar characteristics and meet the same needs from the point of view of consumers, the test being whether their use is comparable, and where the differences between them do not have a significant influence on the decision of the average consumer to use one or the other of those services (alternative criterion), or must it take into account other criteria such as the existence of a discretionary power on the part of the Member State to exempt certain categories of games from VAT and to subject others to it, the fact that lotteries belong to a distinct category of games, referred to in Article 135(1)(i) of the VAT Directive, the different legal frameworks which apply to Loterie Nationale and to other games of chance, the different supervisory authorities or the societal and gambler protection objectives pursued by the legislation applicable to Loterie Nationale?

3.

Must the principle of sincere cooperation set out in Article 4(3) TEU, read in conjunction with Article 267 TFEU, the provisions of the VAT Directive and, where applicable, the principle of effectiveness, be interpreted as meaning that they allow the constitutional court of a Member State to maintain — on its own initiative and without a reference for a preliminary ruling under Article 267 TFEU — on the basis of a provision of national law — in this case Article 8 of the loi spéciale du 6 janvier 1989 sur la Cour constitutionnelle (Special Law of 6 January 1989 on the Constitutional Court) — the retrospective effect of national provisions on value added tax which were found to be contrary to the national Constitution and were annulled on that ground and whose non-conformity with EU law was also relied on in support of the action for annulment before the national court, without, however, that complaint having been examined by the latter, on the general ground of ‘budgetary and administrative difficulties which repayment of taxes already paid would cause’, thus completely depriving taxable persons subject to VAT of the right to reimbursement of the VAT collected in breach of EU law?

4.

If the answer to the preceding question is in the negative, do the same provisions and principles, interpreted, in particular, in the light of the judgment of 10 April 2008, Marks & Spencer, C-309/06, under which the general principles of Community law, including that of fiscal neutrality, give a trader who has made supplies a right to recover the sums mistakenly claimed in respect of them (judgment of 10 April 2008, Marks & Spencer, C-309/06), require the Member State concerned to refund to the taxable persons the VAT collected in breach of EU law where, as in the present case, it subsequently follows from a judgment of the Court of Justice, in response to questions referred for a preliminary ruling, that the annulled national provisions are not in conformity with Council Directive 2006/112/EC of 28 November 2006 on the common system of value added tax and that the decision of the Constitutional Court to maintain the retrospective effect of the provisions annulled by it is not in conformity with EU law?

5.

Does the different treatment introduced by Articles 29, 30, 31, 32, 33 and 34 of the loi-programme du 1er juillet 2016 (Programme Law of 1 July 2016), which were annulled by Constitutional Court judgment No 34/2018 of 22 March 2018, but the effects of which were maintained after that date in respect of the taxes already paid for the period from 1 July 2016 to 21 May 201[8], between lotteries, whether terrestrial or online, and other online games and forms of betting create a selective advantage in favour of the operators of those lotteries and thus aid granted by the Belgian State or through Belgian State resources which distorts or threatens to distort competition by favouring certain undertakings, which is incompatible with the internal market within the meaning of Article 107 TFEU?

6.

If the answer to the preceding question is in the affirmative, does the obligation on the Member States to safeguard the rights of individuals affected by the unlawful implementation of the aid in question, in accordance with, inter alia, the judgment of 5 October 2006, Transalpine Ölleitung in Österreich, C-368/04, the principle of sincere cooperation and the general principles of Community law, including that of fiscal neutrality, which give a trader who has made supplies a right to recover the sums mistakenly charged in respect of them (judgment of 10 April 2008, Marks & Spencer, C-309/06), allow taxable persons who have been charged VAT on the basis of unlawful State aid to recover the equivalent of the tax paid in the form of damages for the loss suffered?