Since the entry into force of the Treaty of Lisbon on 1 December 2009, the codecision procedure, renamed the ‘ordinary legislative procedure’, has become the main legislative procedure within the decision-making system of the European Union (EU). The ordinary legislative procedure is set out in Article 294 of the Treaty on the Functioning of the EU. It is based on the principle of parity between the European Parliament and the Council and indicates that neither of these two institutions is able to adopt a legislative instrument without the other’s consent.