The EU's national governments unanimously decided in 1992 to lay down in the EU treaty where the EU institutions are officially seated.

This decision had important consequences for the working arrangements for the Parliament: its official seat and the venue for most of the plenary sessions officially became Strasbourg; parliamentary committees were to have their meetings in Brussels; and Parliament's Secretariat (its staff) would be officially based in Luxembourg. In 1997 this whole arrangement was incorporated into the EU treaty.

Any change in the current system would need changing the treaty, which requires unanimity among all member states governments and ratification by each of their national parliaments.