The European Parliament plays an essential role in the EU decision-making process as co-legislator together with the Council.

The vast majority of European laws are adopted jointly by Parliament and the Council, following a proposal from the European Commission. The procedure is known as the ordinary legislative procedure or co-decision.

In some cases, the European treaties provide for special legislative procedures, such as consultation and approval, in which Parliament is not on equal footing with the Council as in the ordinary legislative procedure.

Parliament's work on a legislative text begins once a proposal is received from the Commission, the institution that initiates the legislative process. The proposal is transmitted to a committee and a Member of the European Parliament is appointed to draft a report. This MEP is known as the rapporteur. When legislation addresses general issues, co-rapporteurs from different committees may be appointed.

After debates between representatives of political groups and consultations seeking a compromise, the parliamentary committee votes on the draft report and possibly amends it. After the text is reviewed and adopted in plenary, Parliament has adopted its position.