2.12.2009 Official Journal of the European Union L 315/51 EUROPEAN COUNCIL DECISION of 1 December 2009 adopting its Rules of Procedure (2009/882[EU) THE EUROPEAN COUNCIL, Having regard to the Treaty on the Functioning of the European Union, and in particular Article 235(3) thereof, Whereas: (1) The Treaty of Lisbon transforms the European Council into an institution of the European Union. (2)  The European Council should therefore adopt its Rules of Procedure. (3)  To enable these Rules of Procedure to be adopted immediately on the day on which the Treaty of Lisbon enters into force, this Decision should provide that the European Council may use the written procedure laid down in Article 7 of its Rules of Procedure for the adoption of those Rules of Procedure, HAS ADOPTED THIS DECISION: Article 1 1. The European Council hereby adopts its Rules of Procedure, as set out in the Annex. 2. For the adoption of its Rules of Procedure, the European Council may use the written procedure laid down in Article 7 of those Rules of Procedure. Article 2 This Decision shall take effect on the day of its adoption. It shall be published in the Official Journal of the European Union. Done at Brussels, 1 December 2009. For the European Council The President H. VAN ROMPUY