The Procurement Directive, officially Directive 2004/18/EC of the European Parliament and of the Council of 31 March 2004 on the coordination of procedures for the award of public works contracts, public supply contracts and public service contracts (OJ 30.4.2004 L 134/114), has been amended several times, so this is a referral to the consolidated version 1 January 2008:
The Procurement Directive 2004/18/EC is based on the following provisions of the Treaty establishing the European Community (TEC):
Article 47(2) TEC on the right of establishment as self-employed persons,
Article 55 TEC relating to the freedom to provide services.
Article 95 TEC relating to measures for the approximation of laws for the establishment and functioning of the internal market.
The directive was issued according to the so called co-decision procedure (Article 251 TEC).