Theresa May will trigger article 50 of the Lisbon Treaty on March 29th, but it could take up to two months for negotiations to start on Britain’s withdrawal from the European Union. EU leaders will meet in late April to agree their negotiating strategy and the European Commission will receive a detailed negotiating mandate the following month.

“We want negotiations to start promptly, but it’s obviously right that the 27 have the opportunity to agree their position. We fully expect they will want to do that in advance,” the prime minister’s official spokesman said.

European Council president Donald Tusk said on Monday that he would respond within 48 hours to Ms May’s letter next week, formally notifying him of Britain’s intention to leave the EU. Ms May’s letter is expected to outline the shape of the exit deal she hopes to negotiate and Mr Tusk will publish draft negotiating guidelines for the EU.

The other 27 EU leaders will meet in Brussels in late April to approve the guidelines, and officials will spend the next few weeks formulating a detailed negotiating mandate for the European Commission, which will lead the negotiations with Britain under Michel Barnier.

What is Article 50? Article 50 of the Lisbon Treaty sets out how an EU country might voluntarily leave the union. Article 50 says: “Any member state may decide to withdraw from the union in accordance with its own constitutional requirements.” No country has ever invoked Article 50 – yet. Article 50 explained: read more I found this helpful Yes No

Brexit secretary David Davis, who will lead Britain’s negotiating team, said on Monday he hoped to agree a deal that would benefit both Britain and Europe.

“We are on the threshold of the most important negotiation for this country for a generation. The government is clear in its aims: a deal that works for every nation and region of the UK and indeed for all of Europe – a new, positive partnership between the UK and our friends and allies in the European Union,” he said.

‘Extreme and divisive’

“She has chosen the hardest and most divisive form of Brexit, choosing to take us out of the single market before she has even tried to negotiate. That’s why we believe the people should have the final say over the Conservative Brexit deal. Membership of the single market is vital for the British economy and for the jobs of millions of British people. Leaving the single market was not on the ballot paper in the referendum, it is a political choice made by Theresa May,” he said.

Downing Street on Monday sought to end speculation that Ms May would call a snap election, perhaps as early as the beginning of May. Under the Fixed Term Parliament’s Act, the current parliament will run until 2020, and the prime minister’s official spokesman said that she remained opposed to an early election.

“There is no change in our position. There isn’t going to be one,” the spokesman said.