The Treaty of Lisbon empowers COSAC to submit any contribution it deems appropriate for the attention of the European Parliament, the Council and the Commission.
Contributions from COSAC are however not binding on national Parliaments in any way and do not in any way prejudice their positions.
In 1991 COSAC adopted its own Rules of Procedure, comprising provisions on the organisation of work in this forum. COSAC made comprehensive amendments to these Rules of Procedure at the XLVth COSAC meeting, which was held in Budapest from 29th to 31st May 2011.
Chair and members
COSAC meetings are always organised by the national parliament of the Member State that holds the rotating Presidency of the European Union at the time. The parliament that hosts the COSAC meeting also chairs this meeting. COSAC's Rules of Procedure stipulate that six parliamentarians from each Member State and six members of the European Parliament may attend COSAC meetings.
In the case of the Federal Republic of Germany, the German Bundestag and the Bundesrat have agreed that the German delegation shall be comprised of members of both federal legislative bodies in a ratio of 4:2.
The body known as the "troika" draws up the agenda for COSAC meetings in agreement with the European Parliament. This troika is made up of the chairs of the parliamentary Committees on European Affairs from the Member States of the current, preceding and subsequent Council Presidency, along with representatives from the European Parliament.
COSAC decisions have to date always been made unanimously.
COSAC positions are generally decided upon on a consensus basis. Should this not be possible, COSAC positions may be adopted by a qualified majority of three-quarters of the votes cast, in conjunction with a 50-percent quorum of all COSAC parliaments. Each delegation has two votes. For Member states with a bicameral system, this signifies that each parliamentary representative body has one vote. The rules of procedure may only be amended by a unanimous vote.
In addition, COSAC adheres to the Guidelines for Interparliamentary Cooperation in the European Union, adopted by the Conference of Speakers at their meeting in Lisbon from 19th to 21st June 2008.
A permanent Brussels-based COSAC Secretariat was established on 1st January 2004. The Secretariat's work includes providing support to each Presidency Parliament in preparing and organising COSAC meetings.
The Bundesrat is usually represented at COSAC meetings by the chair of the Committee on European Union Questions and/or by one or two other members of this committee.