Arch-Brexiteer Jacob Rees-Mogg said he did not believe there would be a vote of confidence in Mrs May by Tory MPs, but called on her to change her Brexit stance as he attacked the Cabinet deal on European Union withdrawal hammered out at a summit at Chequers last week.
Sky News has been told that Brexiteers have "plenty more in the locker" as they seek to "inflict as much damage as possible" on Mrs May and try to force her to change course.
The government will tomorrow publish its Brexit white paper, which will set out in more detail the UK's trade negotiating position, agreed at Chequers, which has prompted the resignation of two Cabinet ministers, one junior minister, two vice chairs and at least two parliamentary private secretaries (PPS).
Two Brexit disruptors, two very different resignations.
May, having finally signalled her vision for Brexit, spent two hours in parliament defiantly defending the plans and called for Brussels to engage fully or risk the damaging prospect of Britain leaving the bloc with no deal in place.
Still, he laid out his principled rationale as the lead cabinet officer in charge of selling a plan in which he did not believe.
His resignation this afternoon from the Foreign Office, in response to May's Soft Brexit plan agreed at Chequers on Friday, and following the resignation of Brexit secretary David Davis last night, ends a period of political prevarication we haven't seen since Boris Johnson couldn't make up his mind about whether to back Leave or Remain at the European Union referendum. Theresa May's song, unfortunately, stuck in his throat.
I can only regret that the idea of Brexit has not left with Davis and Johnson.
Is this the end to the cabinet resignations?
Former Conservative MP Ann Widdecombe has warned that a new Brexit policy rolled-out by British Prime Minister Theresa May is unacceptable.
But many eurosceptic MPs are outraged at May's plan, and Davis's resignation letter was scathing.
Senior lawmakers in her party said they did not expect the prime minister to face a vote of no confidence, although some Conservatives were still saying that she should go.
But recent polling figures should provide the Conservatives little comfort: Only 29 percent of Britons polled approve of the government's handling of Brexit. But, after much speculation, Mr Johnson announced he would not enter the Conservative leadership race when his ally Michael Gove announced he was running.
Yet he and Johnson have shared a mutual affinity for one another, so his departure may put the already tenuous USA -U.K. relationship on even shakier ground, especially if May enters into conversations with Trump from a weakened position.
Noting that the U.K.is in political turmoil before departing for Europe, President Trump failed to offer a word of encouragement in support of Theresa May, observing that her future was "up to the people".
At 3pm on Monday, a statement was issued by Downing Street to say: "This afternoon, the Prime Minister accepted the resignation of Boris Johnson as Foreign Secretary".
On Monday night, while addressing her backbenchers, May said without their support, Corbyn could run the country as prime minister.
The Prime Minister was greeted by loud cheers from Tory MPs and shouts of "resign" from the opposition benches as she arrived to deliver a statement in which she said her proposals would deliver "a Brexit that is in our national interest... the right Brexit deal for Britain".