The Council of the European Union is the EU's main decision-making institution. It was formerly known as the 'Council of Ministers', and for short it is simply called 'the Council'.

The European Parliament is the elected body that represents the EU's citizens and takes part in the legislative process.

The Commission is one of the EU's key institutions. Until 1 May 2004 it had 20 members (two each from France, Germany, Italy, Spain and the United Kingdom, one from each of the other countries), appointed for a five year period by agreement between the Member States, subject to approval by Parliament.

The Court of Justice of the European Communities, located in Luxembourg, is made up of one judge from each EU country, assisted by eight advocates-general. They are appointed by joint agreement of the governments of the member states. Each is appointed for a term of six years, after which they may be reappointed for one or two further periods of three years. They can be relied on to show impartiality.

In June 2004, the member states agreed the text of a future Constitution for the EU. The Constitution aims to provide the Union with a set of ground rules to govern the functioning of its institutions. Before the Constitution enters into force, all members states have to approve it by referendum or the act of parliament.