The composition of the European Council would undergo one change under the Treaty of Lisbon. The President of the European Council would become a member, according to Article 15(2) of the amended Treaty on European Union (TEU).
The head of state or government of each member state would still be a member, as would the President of the Commission, as under the current Article 4 TEU.
Article 15(2) TEU (Lisbon)
2. The European Council shall consist of the Heads of State or Government of the Member States, together with its President and the President of the Commission. The High Representative of the Union for Foreign Affairs and Security Policy shall take part in its work.
(OJEU 9.5.2008 C 115/23)
Members first class
The heads of state or government would vote, if and when the European Council makes a decision by voting.
Members second class
The President of the European Council (chairman) and the President of the Commission do not have the vote, according to Article 235(1) of the Treaty on the Functioning of the European Union (TFEU).
The High Representative of the Union for Foreign Affairs and Security Policy would take part in the work of the European Council.
The Council meets in different configurations, of which the existing General Affairs and External Relations Council (GAERC) mentioned in Article 2 of the Council’s Rules of Procedure is most closely linked to the European Council through its coordinating functions and its subject matter, external relations.
The Treaty of Lisbon splits the GAERC into two different Council configurations: the coordinating General Affairs Council (GAC) and the Foreign Affairs Council (FAC) (Article 16(6) TEU Lisbon).
(Preparatory work is needed for the implementation of the Lisbon Treaty.)
The High Representative chairs the Foreign Affairs Council (FAC), which means that it would be represented at the meetings of the European Council without the Foreign Ministers of the member states (Article 27(1) TEU Lisbon).
As we will see, this has immediate consequences, but it may have interesting long term implications as well.