Treaty of Accession 2003

The Treaty of Accession 2003 was the agreement between the member states of the European Union and ten countries, concerning these countries' accession into the EU. At the same time it changed a number of points which were originally laid down in the Treaty of Nice.
The treaty was signed on 16 April 2003 in Athens, Greece and it entered into force on 1 May 2004, resulting in enlargement of the European Union with 10 states.

Background

The European Union comprises a large number of overlapping legal structures which is a result of it being defined by successive international treaties.
As well as other acts which together form the current legal framework of the EU, the Treaty of Accession 2003 modifies:

All changes to the above treaties are made by article 11-19 in part two of the accession treaty. Beside of revising voting weights and the number of member state representatives at all European institutions, the most notable change outlined how Qualified Majority Voting shall be handled in the Council of the European Union. As from 1 November 2004, whenever the Council vote to adopt a decision by Qualified Majority, this need support both from a majority of member states which at the same time represents minimum 232 out of 321 weighted votes, while also as a third requirement those states must represent at least 62% of the total population of the Union. Otherwise the decision in question shall not be adopted.
The Treaty's full name in English is: