The Ordinary Legislative Procedure (OLP) is established by Article 294 of the Treaty on the Functioning of the European Union (TFEU) and is identified as the default mode of EU lawmaking by Article 289(1) TFEU. It evolved from the "cooperation procedure" introduced by the Single European Act of 1986 and the "co-decision procedure" created by the Maastricht Treaty in 1993, the latter being substantially streamlined by the Treaty of Amsterdam in 1999. The Lisbon Treaty, entering into force on 1 December 2009, renamed co-decision as the Ordinary Legislative Procedure and extended its scope to roughly 85 policy areas, including agriculture, fisheries, the common commercial policy, and most aspects of justice and home affairs. Under the procedure, the European Parliament and the Council of the European Union act as co-legislators of equal standing, while the European Commission retains a near-monopoly on the right of legislative initiative under Article 17(2) TEU.
The procedure begins when the Commission submits a legislative proposal — typically a draft regulation, directive, or decision — simultaneously to the Parliament and the Council, accompanied by an impact assessment and explanatory memorandum. National parliaments receive the text under Protocol No. 2 and have eight weeks to issue reasoned opinions on subsidiarity grounds (the "yellow card" mechanism). In the first reading, the Parliament adopts its position by simple majority following committee scrutiny led by a rapporteur. The Council then either approves Parliament's position — in which case the act is adopted — or adopts its own position by qualified majority (defined under Article 16(4) TEU as 55% of member states representing 65% of the EU population) and transmits it back to Parliament with a full explanation of reasoning.
If disagreement persists, the second reading begins. Parliament has three months (extendable by one) to approve, reject, or amend the Council's position; rejection requires an absolute majority of component members (currently 361 of 720 MEPs), and amendments likewise require an absolute majority. The Council then has three months to accept Parliament's amendments by qualified majority — or unanimously where the Commission has issued a negative opinion. Failure to agree triggers convocation of a Conciliation Committee composed of an equal number of Council representatives and MEPs, which has six weeks to negotiate a joint text. If the committee produces a joint text, both institutions must approve it in a third reading within six weeks; otherwise the act fails. In practice, the great majority of files are concluded at first reading through informal "trilogues" — closed-door negotiations among Parliament, Council, and Commission representatives — codified by the 2016 Interinstitutional Agreement on Better Law-Making.
Recent practice illustrates the procedure's range. The Artificial Intelligence Act (Regulation 2024/1689), proposed by the Commission in April 2021 and politically agreed in December 2023, was adopted under OLP after intensive trilogues led by co-rapporteurs Brando Benifei (S&D) and Dragoş Tudorache (Renew). The Digital Services Act and Digital Markets Act (2022), the Carbon Border Adjustment Mechanism (Regulation 2023/956), and the Migration and Asylum Pact concluded in spring 2024 all proceeded under OLP. Negotiations typically involve the Council's rotating Presidency — held by Belgium in the first half of 2024, Hungary in the second, and Poland in the first half of 2025 — coordinating member-state positions through COREPER, while Parliament's position is shaped by its lead committee and shadow rapporteurs from each political group.
The OLP must be distinguished from special legislative procedures under Article 289(2) TFEU, in which either the Council or (rarely) the Parliament acts as sole legislator while the other institution is merely consulted or required to consent. Taxation, the EU's own-resources system, the multiannual financial framework, and most Common Foreign and Security Policy matters remain under special procedures or intergovernmental decision-making, frequently requiring Council unanimity. The OLP is likewise distinct from the delegated and implementing acts regimes under Articles 290 and 291 TFEU, which govern secondary executive rule-making by the Commission subject to comitology controls.
Several controversies attend the procedure. The dominance of trilogues has been criticised by the European Ombudsman (notably in 2015 inquiry OI/8/2015) and by academics for opacity, since informal trilogue documents are not routinely published and the Court of Justice's De Capitani judgment (T-540/15, 2018) ordered greater disclosure of four-column negotiating documents. The unanimity requirement that survives in adjacent fields — taxation, foreign policy, enlargement — has fuelled debate over extending OLP through the "passerelle" clauses of Article 48(7) TEU, a proposal advanced by the Conference on the Future of Europe (2022) and endorsed by the Franco-German Group of Experts on EU Institutional Reform in September 2023. Brexit removed 73 MEPs and recalibrated qualified-majority arithmetic from 1 February 2020.
For the working practitioner — whether a permanent representation desk officer in Brussels, a ministry legal adviser in a capital, or a Washington-based analyst tracking transatlantic regulatory divergence — mastery of OLP timing is operationally indispensable. Trilogue calendars, Presidency priorities, rapporteur appointments, and COREPER mandates determine when lobbying windows open and close. Because OLP-adopted regulations apply directly across 27 member states and influence global standards through the "Brussels effect," tracking a file from Commission proposal to Official Journal publication is now a core competency in foreign ministries, regulatory agencies, and multinational government-affairs functions worldwide.
Example
The European Parliament and Council adopted the Artificial Intelligence Act under the Ordinary Legislative Procedure in 2024, concluding trilogues that began under the Spanish Council Presidency in December 2023.