Article 50 will be triggered on March 29

British trade officials are discreetly exploring a 10-year interim arrangement with the European Union in case a trade deal is not reached during Britain's exit negotiations, writes Politico.

An EU spokesman said it was "ready and waiting" for the letter.

Mrs May's spokesman appeared to rule out an early general election at the same time as revealing the date of Brexit, saying: "There is not going to be one".

As per May's Ocotber speech on the subject, the letter formally submitting parliament's intention to start the Brexit process was expected to reach the European Union by the end of March.

The prime minister's spokesman has confirmed that Theresa May will trigger article 50 on Wednesday, March 29, initiating the formal process for the United Kingdom to leave the EU.

The notification of Article 50 will take the form of a letter to Tusk, likely outlining Britain's key objectives, followed by a statement by May to MPs in the House of Commons. "We want negotiations to start promptly but it's obviously right that the 27 have an opportunity to agree their position".

Stephen Gethins, the SNP's Europe spokesman, said: "Today's announcement that the Prime Minister will push ahead and unilaterally trigger Article 50 shatters beyond fix any notion or position that the Prime Minister is seeking a UK-wide agreement".

The move comes nine months after Britain voted 51.9 percent to 48.1 percent in favour of Brexit in a referendum on 23 June, 2016.

After almost a year of phoney war since the June 23 referendum vote to quit, British negotiators led by Brexit Secretary David Davis will sit down with the European Union, possibly still in May.

"The government is clear in its aims", he said.

"The government is clear in its aims: a deal that works for every nation and region of the United Kingdom and indeed for all of Europe - a new, positive partnership between the United Kingdom and our friends and allies in the European Union", Davis added.

The EC is expected to provide an initial answer to Britain's Article 50 notification within 48 hours, but negotiations are not expected to start for several weeks or even months.

Britain's exit negotiations are expected to be exceptionally tricky, with the country aiming to leave Europe's common market and customs union but hoping to retain preferential access to both through a new trading agreement. "There is a timetable that everyone has bought into it".

It warns that this will mean ministers having to achieve a fine balancing between giving too little parliamentary scrutiny or too prolonged, in-depth examination to Brexit-related legislation.

May has said she believes that "no deal is better than a bad deal".

Barnier has said that he expects a deal to be agreed in 2018 and ratified in 2019.

Although Britain as whole voted to leave the EU, Scotland and Northern Ireland voted to stay in the bloc.

Mr Farron repeated his call for voters to have the final say on the deal negotiated by Mrs May, arguing that departure from the European Single Market was not on the ballot paper in June.

  • Elsie Buchanan