The European Parliament (EP) is, along with the Council of the EU , the European Commission and the European Court of Justice , one of the key institutions of the European Union (EU). Directly elected every 5 years throughout the 27 Member States of the EU, it is a multinational, multilingual parliament of 736 members and 23 languages.

The EP's main job is to help provide democratic accountability of EU decisions, to ensure that the right decisions are taken both in the light of the EU as a whole and of specific national and regional concerns. The EP's role is thus complementary to that of national parliaments, who must ensure democratic accountability of the European decisions taken by their own national governments. The EP's powers have evolved steadily since the first direct elections in 1979, when it was still essentially a consultative body. It now has a range of significant powers:

The EP shares European legislative powers with the Council of the EU, and examines, modifies and occasionally rejects legislative proposals from the European Commission. In some fields its role is still consultative, but in many others, in areas as important as the environment, transport, social policy and food safety, it has full powers of codecision.

The Services Directive and REACH, the chemicals regulation, are just two recent examples of major European legislation which the EP played a decisive role in shaping. The EP takes part in EU legislative planning, and can ask for new issues to be placed on the EU agenda.

The EP shares budgetary powers with the Council of the EU. It has a particularly powerful role in adopting (or again even rejecting) the annual EU budget, and helping to distribute financial resources between different Community programmes. It has an important say on the shape of longer-term EU expenditure, and on the financial resources available for these purposes.

The EP plays a role in monitoring the negotiations between the EU and countries such as Croatia or Turkey which wish to become EU Member States. At the end of the negotiating process, the EP has to give its assent to the outcome. If the EP says no, there is no appeal mechanism.

The EP now plays a decisive role in the appointment of the President of the European Commission and of the Commission as a whole. It can fire the entire Commission if dissatisfied with its performance. The EP elects the EU Ombudsman and has a growing role in choosing the members of the European Central Bank, the European Court of Auditors and the Directors and certain members of the Management Boards of many EU agencies.

The EP is now taking a closer interest in whether adopted EU legislation is being properly implemented and is meeting its original objectives, or should be modified, simplified or even replaced. Its budgetary control powers are considerable, and it has to give its agreement to the overall annual use of EU funds.

Finally, the EP plays an important role in looking at the future shape and powers of the EU. It provided a number of members to take part in the Convention which helped to draw up the draft European Constitution and took an active part in the negotiations which led to the current Lisbon Treaty.