Conference of Parliamentary Committees or Union Affairs of the Parliaments of the European Union.
A special co-operation between the national parliaments about European affairs. Has a legal base in a Treaty protocol on co-operation among the national parliaments.
COSAC has decided to maintain a common secretariat in Brussels and to co-ordinate its positions on Treaty changes and other topics. COSAC is led by the country which holds the current presidency of the European Union.
In 2006 COSAC and the national parliaments have been assigned the task of assessing initial EU legislation in terms of the principles of subsidiarity and proportionality.
In January 2014 the Danish Parliament sent 23 proposals for better cooperation. The Dutch Palriament also sent proposals.