According to the Treaty of Lisbon, any European state which respects the EU’s founding values and is committed to promoting them may apply to become a member of the European Union.
Although the Commission does the donkey work, the decisive steps of the accession process are intergovernmental, with the European Council, the Council as well as the member states’ governments and parliaments in key roles.
There are three groups of criteria for eligibility:
1) European state has not been defined, but in 1987 Morocco’s application to join the European Community was rejected on the grounds that it was not a European state. .
2) The values Article 49 of the amended Treaty on European Union (TEU) refers to are mentioned in Article 2 TEU: respect for human dignity, freedom, democracy, equality, the rule of law and respect for human rights, including the rights of persons belonging to minorities (OJEU 9.5.2008 C 115).
3) The conditions of eligibility agreed upon by the European Council shall be taken into account. The current criteria have been laid down by the European Council in Copenhagen (1993) and Madrid (1995).
The applicant state addresses its application to the intergovernmental Council. The Council consults the Commission and needs the consent of the European Parliament for a decision to open membership negotiations.
Even if the formal decision is taken by the Council, unanimously, almost everyone would agree that the decisive political green light is given by the European Council.
The donkey work of conducting the accession negotiations is delegated to the Commission, but regulated and keenly followed by the Council. The applicant state has to adopt the existing Community legislation (acquis communautaire), and the negotiations advance Chapter by Chapter (35 in all).
The accession treaty is concluded intergovernmentally, between the member states and the applicant state, subject to ratification by all of them.