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Treaty of Nice



Treaty of Nice


  • The treaty prepares the EU for its biggest single enlargement, with 10 new member countries (Czech Republic, Cyprus, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia and Slovenia) to join the EU in May 2004 and 2 more (Bulgaria and Romania) in January 2007.
  • It amends the Treaty on European Union (TEU) and the Treaty establishing the European Community (TEC).
  • Concretely, the treaty reforms the EU institutions so that they can function efficiently in an enlarged EU of 27 member countries – something that the Amsterdam Treaty was intended to do but had failed.


Making the EU institutions more legitimate and more efficient in the perspective of the EU’s expanded membership

  • The method for defining the composition of the European Commission is changed:
    • the composition of the Commission is progressively changed from 2 commissioners for the larger countries (France, Germany, Italy, Spain and the United Kingdom (1)) and 1 for the other countries, to a maximum number of 27 commissioners, with each member country having the right to designate a commissioner by rotation on a strictly equal basis;
    • the president of the Commission and the commissioners are from now on designated by means of a qualified majority in the Council;
    • the president of the Commission receives increased powers over the college of commissioners, namely to distribute or reorganise responsibilities among commissioners and – with approval of the college on simple majority – to dismiss one of the commissioners.
  • The voting system in the Council of the European Union is redefined:
    • the weighting of votes is rebalanced to better reflect the relative populations of the member countries;
    • the conditions for obtaining a qualified majority are strengthened, with now 73.9% (instead of 71.3%) of the votes needed, as well as the majority of EU countries representing (if this verification is required by an EU country) at least 62% of the EU population;
    • the use of qualified majority voting is extended to new areas.
  • The composition of the European Parliament is revised and its powers are increased:
    • the number of seats is increased to 732 members in the EU of 27 member countries;
    • the codecision procedure (today ordinary legislative procedure) is extended to almost all the areas where the Council decides on qualified majority;
    • the Parliament can take a matter to the Court of Justice of the EU just like a member country or the Commission.
  • The Court of Justice of the European Union is radically reformed:
    • it will sit in different formations: in chambers of 3 to 5 judges, in grand chamber (11 judges) or in plenary session (1 judge per EU country);
    • the competencies of the Court of First Instance (now, the General Court) are extended, namely to some categories of reference for a preliminary ruling*;
    • the Council acting unanimously can create subsidiary courts to deal at first instance with special areas of law, such as patents.
  • New rules on enhanced cooperation are introduced:
    • it involves only a minimum of 8 EU countries (not a majority like before);
    • in the core European Community ‘pillar’, an EU country no longer has the possibility to veto the launch of enhanced cooperation. Moreover, alongside Commission approval (always necessary), the assent (or today, consent) of the Parliament is now required if the area of cooperation is one where there is codecision;
    • the possibility of enhanced cooperation is extended to the common foreign and security policy, to the exclusion of defence and here with a power of veto of the EU countries;
    • in cooperation in justice and home affairs, enhanced cooperation is made particularly flexible: there is no veto power of the EU countries and neither the approval of the Commission or of the Parliament is required.

Main other changes brought about by the treaty

  • Alongside the possibility of sanctions against an EU country for violation of fundamental rights by an EU country (introduced by the Amsterdam Treaty) a preventive mechanism is added in Article 7 of the TEU.
  • The TEU is modified to take into account the developments of the European security and defence policy.
  • The role of Eurojust for the development of judicial cooperation in criminal matters is recognised.
  • Brussels is designated as the venue for formal European Council meetings.


Signed on 26 February 2001, the treaty entered into force on 1 April 2003. Some of its rules however started to be implemented at a later date.


For more information, see:


Preliminary ruling: a ruling by the Court of Justice of the European Union in reply to a question from a national court on the interpretation or validity of European law, thereby contributing to the uniform application of EU law.


Treaty of Nice amending the Treaty on European Union, the Treaties establishing the European Communities and certain related acts (OJ C 80, 10.3.2001, pp. 1–87)


Treaty on European Union – consolidated version 1992 (OJ C 191, 29.7.1992, pp. 1-112)

Treaty establishing the European Community – consolidated version 2002 (OJ C 325, 24.12.2002, pp. 33-184)

last update 21.03.2018

(1) The United Kingdom withdraws from the European Union and becomes a third country (non-EU country) as of 1 February 2020.