UK withdrawal from the EU

The United Kingdom's withdrawal from the European Union (EU), commonly called "Brexit", is the result of a majority of British voters deciding to leave the EU in the referendum on the issue on 23 June 2016. Prime Minister Theresa May invoked Article 50 of the Treaty on the European Union on 29 March 2017, starting the two-year period of withdrawal negotiations. The UK is therefore set to leave the EU by April 2019.

The terms of withdrawal have not yet been negotiated, and the UK remains a full member of the European Union. May said that the UK government would not seek permanent single market membership, and promised a Great Repeal Bill that would repeal the European Communities Act and would incorporate existing European Union law into the domestic law of the UK.

The UK joined the European Communities, the predecessor of the EU, on 1 January 1973. A referendum in 1975 approved its membership. In the 1970s and 1980s, withdrawal from the EC was advocated mainly by Labour Party and trade union figures. From the 1990s, the main advocates of withdrawal from the EU were the newly founded UK Independence Party (UKIP) and an increasing number of Conservative MPs.

...
Wikipedia