"The direct consequences of that will be Prime Minister Corbyn".
Addressing the USA president in front of an audience of business leaders and senior ministers, Mrs May said: "As we prepare to leave the European Union, we have an unprecedented opportunity to do more".
The policy paper, which sets out plans for close economic ties with the bloc after Britain leaves the European Union in March, had already sparked two ministerial resignations and revived talk of a revolt against Ms. May.
May has faced a backlash over the plan from Brexit hardliners in her Conservative Party who say it gives too many concessions to the European Union, but she has support from moderates and there has been no challenge to her leadership. One described accepting European Union rules as "the ultimate betrayal".
Some Conservative Brexit supporters are still incensed over what they see as her breach of a promise to break cleanly from the EU.
May's survival will depend on keeping other senior cabinet ministers in the government.
The Prime Minister enduring a bruising battle today as the two Cabinet heavyweights resigned over Brexit.
Former Chelsea captain Terry pays tribute to sacked Conte
Sarri could be followed by midfielder Jorginho from Napoli, with Chelsea willing to pay £50m, plus £7m in bonuses, for the pair. However, the club finished fifth a year ago and there were rampant rumours that the Italian was going to leave.
May must now move quickly to try to win the EU's support for her Brexit proposal to unblock talks.
There was no immediate statement from Johnson, another loud pro-Brexit voice within May's divided government. "It's not even an accidental betrayal, it was planned and plotted well in advance", said Conservative lawmaker Andrew Bridgen.
And finally John Cleese is moving to "one of the nicest island" he has been to because he is fed up over the lies on both sides of the Brexit debate and really fed up with the press he told Emily Maitlis on BBC Newsnight. The tousle-headed blond Johnson is one of Britain's best-known politicians, and one of the most prominent advocates for Brexit. "She's in office but not in power".
Barnier said the need to uphold the EU's rules applied also in the area of financial services because "what is at stake is the financial stability of the European Union".
Davis himself expressed regret that Johnson had quit, and said it would be "wrong" for his departure to trigger a major rebellion. The Daily Telegraph newspaper ran a photograph on Tuesday of him, pen poised, resigning as foreign minister. Three junior ministers also quit their posts.
The Brexit group of the parliament, which has a right of veto over the deal, said a comprehensive deal, covering economic, foreign and security policy, had been the parliament's preferred option from the start.
Boris Johnson has launched a scathing attack on Theresa May's Brexit strategy, saying the "dream is dying, suffocated by needless self-doubt".
Hunt said it was a moment to show that Britain remained a "strong, confident voice in the world".
"Now there is chaos", the paper said in its editorial.