National governments retain substantial decision-making authority on taxation, social security, and foreign policy. Supranational body an institution or organisation which has decision-making authority independent of its member states. Intergovernmental body an institution or organisation based on cooperation between nation-states. Integration moved up a gear in the mid-1980s as member states pressed for further economic integration to improve Europe’s competitive position. The Maastricht Treaty, properly known as the Treaty on European Union, was agreed in 1991 and came into force in 1993. One of the most visible results of the 2004 enlargement has been the westward migration of workers from new member states, although a number of states imposed short-term restrictions. Agreement on institutional reform had to wait until an ill-tempered European Council meeting at Nice in 2000. The Nice Treaty did not come into force until 2003 after a second referendum in Ireland reversed an initial ‘no’ vote.