On 1 may 2004, 10 new Member States joined the European Union. This meant inter alia that, save for the express derogations provided for in the Act of Accession, the entire mass of Community secondary legislation became binding in the new Member States. This principle of the immediate effects of Community law in the new Member States was provided for in Article 2 AA:
From the date of Accession, the provisions of the original Treaties and the acts adopted by the institutions and the European Central Bank before Accession shall be binding on the new Member States and shall apply in those States under the conditions laid down in those Treaties and in this Act.