Treaty establishing the European Union (EU). Agreed in 1991 and signed in 1992, the treaty took effect on 1 November 1993 following ratification by member states. It advanced the commitment of member states to economic and monetary union (but included an opt-out clause for the United Kingdom); provided for intergovernmental arrangements for a common foreign and security policy; increased cooperation on justice and home affairs policy issues (though the Social Chapter was rejected by the UK until a change of government in 1997); introduced the concept of EU citizenship (as a supplement to national citizenship); established new regional development bodies; increased the powers of the European Parliament; and accepted the principle of subsidiarity (a controversial term defining the limits of European Community involvement in national affairs).
Denmark rejected the treaty at first, and then accepted it, in national referendums in June 1992 and May 1993. The original ‘no’ vote, together with the UK's and Italy's later enforced withdrawal from the European Exchange Rate Mechanism, affected the entire European Community. The French only narrowly voted in favour in September 1992 and a British government proposal to go ahead with ratification in November 1992 was passed by only a small parliamentary majority, prompting the then British prime minister, John Major, to delay ratification until after a second Danish national referendum. These results contrasted with a clear ‘yes’ vote in lower-income countries such as Spain and Ireland, which stood to benefit substantially from the treaty.
By the end of 1992, all parliaments, apart from those of Denmark and Britain, had completed ratification, and at a summit in Edinburgh in December 1992, a series of compromises was agreed, including limited Danish participation. Denmark subsequently ratified the treaty in May 1993, followed by the UK in July.