Shocking documents show there is a high chance Brexit will remain in name only for years.
Cabinet ministers were warned Mrs May’s much-debated Chequers plan “could, in theory, lead to a long-running implementation period”.
The transition period is set to last for almost two years, from March 29 2019, when the UK formally withdraws from the EU, to December 2020.
However, these documents made clear Britain could be tied to the bloc for much longer than that.
The leaked papers, seen by The Times, said a possible extension of the transition period would be evaluated on a “rolling” basis with an “annual decision point”.
The revelation clashes with what Mrs May said last week, when she argued the transition period could be extended, but only for “a few months”, just to ultimate details.
The Prime Minister confirmed her desire to see Britain detaching the bloc by 2020 during her speech to parliament on Monday, where she told MPs the implementation plan would end “well before the end of this parliament”, in 2022.
The leak comes as Sir Edward Leigh MP joined the Stand Up 4 Brexit grassroots group, which campaigns against the Chequers plan.
He his the 50th MP to back the campaign, which yesterday also joined by Boris Johnson, the former Foreign Secretary.
Upon backing the group, the now leading backbencher said: “With the proposal’s that our Government is putting forward we wouldn’t control our laws, and we certainly wouldn’t be able to do proper Free Trade Deals.
“It is a cheat and a fraud on those who voted to leave.“
In a few hours, the Prime Minister will meet with the feared 1922 Committee, after one unnamed opponent of Mrs May said over the weekend she was in a “killing zone”.
The Prime Minister traditionally plays an important role in choosing the leader of the party.
The 1922 Committee has been receiving letters of no confidence from MPs.
Only 48 letters are needed for a no-confidence vote, which could trigger a leadership contest.
Nigel Farage, former head of the Ukip and leading Brexiteer, called for the prime minister’s resignation from the floor of the European Parliament, who gathered this morning for its monthly plenary session.
Arguing the real enemies of Brexit are not sitting in Brussels but in London, he said: “There is a group of people who don’t wish to find a solution who are putting up a wall, and it isn’t your chief negotiator Michel Barnier, is actually the British civil service.
“They signed up years ago to the European dreams, they are happy to take orders from Brussels, they are out to sabotage Brexit.
“They are the enemy within.
“Unless the Conservative Party gets rid of a leader who is being led by the nose, we will head to the December summit, head for a defeat and a United Kingdom being trapped to the EU for many years to come.”