Brexit (a portmanteau of "British" and "exit") is the withdrawal of the United Kingdom (UK) from the European Union (EU). Following a UK-wide referendum in June 2016, in which 52% voted to leave and 48% voted to remain in the EU, the British government formally announced the country's withdrawal in March 2017, beginning the Brexit process. The withdrawal was delayed by deadlock in the British parliament. Following a general election, Parliament ratified the withdrawal agreement, and the UK left the EU at 11 p.m. GMT on 31 January 2020. This began a transition period that is set to end on 31 December 2020, during which the UK and EU will negotiate their future relationship. The UK remains subject to EU law and remains part of the EU customs union and single market during the transition, but is no longer part of the EU's political bodies or institutions.