On 29 March 2017 the British government gave formal notice of the UK's intention to leave the European Union in a letter to the European Council. The UK is thus expected to withdraw from the EU at the end of March 2019, following the two-year period of negotiation provided under Art. 50 of the Treaty on European Union. However, this may be extended with the consent of the UK and all EU member states. The withdrawal negotiations between the UK and the EU started on 19 June 2017.
Only once the UK's withdrawal from the EU comes into effect, the treaties governing the UK's relations with the EU will cease to apply. The same goes for the agreements that the EU has negotiated with third countries, including the Switzerland–EU bilateral agreements.
The British government set out its negotiation objectives in the White Paper published at the start of February 2017.
On 26 June 2017, the UK government set out its initial offer with regard to the rights of EU citizens living in the UK in a policy paper (see below for more information).