“Brexit is the popular term for the United Kingdom’s prospective withdrawal from the European Union (EU).
In a referendum on 23 June 2016, 51.9% voted to leave the EU. On 29 March 2017, the British government invoked Article 50 of the Treaty on the European Union; although revoking this might be legally possible, the UK is thus on course to leave the EU in March 2019.
Prime Minister Theresa May announced that the UK would not seek permanent membership of the single market or the customs union after leaving the EU and promised to repeal the European Communities Act of 1972 and incorporate existing European Union law into UK domestic law. Negotiations with the EU officially started in June 2017.
The UK joined the European Communities on 1 January 1973, with membership later confirmed by the holding of the first ever national referendum in June 1975. 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 were the newly founded UK Independence Party (UKIP) and an increasing number of Eurosceptic Conservatives.” https://en.wikipedia.org/wiki/Brexit