The procedure is also known as the "Article 251 procedure", as it is laid down in Article 251 of the EC Treaty. The new Treaty of Lisbon replaces all references to the "procedure referred to in Article 251" with references to the "ordinary legislative procedure".
cannot overrule a rejection by the Parliament.
Under the codecision procedure, a new legislative proposal is drafted by the European Commission. The proposal then comes before the European Parliament and the Council of Ministers. The two institutions discuss the proposal independently, and each may amend it freely.
In Council, a new proposal is first considered by a working group for that policy area. The conclusion of the working group's discussions is known as the orientation generale, and usually forms the basis of Council's position at the end of the first reading, which is known as the common position.
Meanwhile, Parliament appoints one of its members as 'rapporteur' to steer the proposal through its committee stage. The rapporteur is responsible for incorporating the committee's amendments into the draft proposal, as well as the recommendations of the Committee of the Regions and the Economic and Social Committee. The finished report is then voted on in full plenary, where further amendments may be introduced.
In order for the proposal to become law, Council and Parliament must approve each other's amendments and agree upon a final text in identical terms. If the two institutions have agreed on identical amendments after the first reading, the proposal becomes law; this happens from time to time, either where there is a general consensus or where there is great time pressure to adopt the legislation.
Otherwise, there is a second reading in each institution, where each considers the other's amendments. Parliament must conduct its second reading within three months of Council delivering its common position, or else Council's amendments are deemed to have been accepted, though this time period can be extended by Parliament if it chooses to do so.
If the institutions are unable to reach agreement after the second reading, a conciliation committee is set up with an equal number of members from Parliament and Council. The committee attempts to negotiate a compromise text which must then be approved by both institutions.
Both Parliament and Council have the power to reject a proposal either at second reading or following conciliation, causing the proposal to fall. The Commission may also withdraw its proposal at any time.
The Lisbon Treaty gives the Parliament more power through extended co-decision
The new Treaty establishing a constitution for Europe, if it enters into force, will extend codecision to virtually all areas of EU policy.
Initially, the codecision procedure applied to the following areas of European policy:
The Treaty of Amsterdam subsequently simplified the procedure, making it quicker and more transparent, and extending it to more areas of policy.
Most recently, the Treaty of Nice established the codecision procedure for any policy area where the Council of Ministers adopts proposals by Qualified Majority Voting (rather than unanimity). The codecision procedure is now by far the most common legislative process in the EU, applying to the vast majority of policy areas.
Besides general criticism that the procedure is long and cumbersome, some critics contend that the codecision procedure gives too much power to the Council at the expense of the Parliament. It could be argued that the process is weighted against the Parliament at second reading, as Parliament may only modify or reject amendments from Council by an absolute majority of MEPs, not just those in the chamber at the time.
Defenders reply that the EU is not a federation and argue that national governments should remain accountable for their collective decisions.