In June 2016, the United Kingdom voted in a referendum to leave the European Union by a margin of 52% to 48%. Nine months later, on 29 March 2017, the Government, by then led by Theresa May, invoked Article 50 of the Treaty on European Union, after Parliament voted to approve the European Union (Notification of Withdrawal) Act 2017 by a vote of 498 to 114. After a General Election in June 2017, May's Conservative Party lost their majority, but were supported by the Democratic Unionist Party to enact their legislative agenda.