Policy background
On 1 January 1973 the UK joined the European Economic Community, which has since evolved to become today’s European Union. A condition of EU membership is that community law, which is now EU law, be given effect in domestic law. The ECA is the principal piece of domestic legislation passed by the UK Parliament that gives effect to EU law in the UK, and gives EU law supremacy over UK domestic law.
	On 23 January 2013 the then Prime Minister announced his intention to negotiate a new settlement on the terms of the UK’s membership of the EU, followed by a pledge to subsequently hold an in-out referendum on the UK’s membership of the EU.
	On 17 December 2015 the European Union Referendum Act 2015 received Royal Assent. The Act made provision for holding a referendum in the UK and Gibraltar on whether the UK should remain a member of the EU. The referendum was then held on 23 June 2016 and resulted in a 52% vote to leave the European Union.
	The European Union (Notification of Withdrawal) Act 2017 was passed into law on 16 March 2017. This gave the Prime Minister the power to notify the European Council of the UK’s intention to withdraw from the European Union under Article 50(2) of the Treaty on European Union. This notification was then given on 29 March 2017. At the same time, the UK notified its withdrawal from the European Atomic Energy Community (‘Euratom’), in accordance with the same Article 50(2) as applied by Article 106a of the Treaty Establishing the European Atomic Energy Community.
	Withdrawing from the EU means the UK will also cease to participate in the European Economic Area (EEA) Agreement as the UK will fall outside the geographic scope of the Agreement and will therefore no longer be a member of the EEA.
	On 2 February 2017 the Government published a White Paper entitled The United Kingdom’s exit from and new partnership with the European Union (Cm 9417) which set out the Government’s vision of what it is seeking to achieve in negotiating the exit from, and new partnership with, the European Union. It set out the twelve principles guiding how the Government will approach the negotiations on the UK’s withdrawal from the EU.
	The Government then published a White Paper on 30 March 2017 entitled Legislating for the United Kingdom’s withdrawal from the European Union (Cm 9446). The White Paper set out the approach to the European Union (Withdrawal) Act and how the domestic legal system will work once the UK leaves the EU.