Corbyn plots May's immediate downfall and prepares to campaign for general election
Theresa May will be expected to stand down if she loses tonight's vote on her Brexit deal as heavily as predicted, UK Cabinet sources have said.
More than 100 Conservative MPs have insisted they will oppose the deal, putting the UK prime minister on course to break a series of unwelcome parliamentary records.
She made a last-ditch attempt to win over the rebels yesterday, producing a letter from Brussels promising the Northern Ireland backstop would be temporary and was "not a threat or a trap".
Tonight Mrs May will make one final bid to change MPs' minds when she closes the five-day debate on the Brexit deal, having already warned the Commons that "when the history books are written", MPs would be judged on whether they had "let the British people down".
If Mrs May loses the vote - expected between 7.30-9.30pm depending on how many amendments are chosen - she is expected to make an immediate statement on her next move.
Last night Labour said leader Jeremy Corbyn would call a no-confidence vote in the Government "within minutes" of a defeat for Mrs May, with such a vote likely to go ahead tomorrow. If the Government lost a confidence vote, a general election could follow.
The prime minister, however, could be gone even before a no-confidence vote could be held in the event that she suffered a record-breaking defeat this evening.
Downing Street declined to deny that Mrs May would resign if she suffered a defeat by a margin well into triple figures and cabinet sources said a defeat by a majority of more than 100 would put Mrs May's future in peril.
Gareth Johnson, a junior whip, resigned from the Government yesterday in order to vote against the EU Withdrawal Agreement, taking the total number of declared Tory rebels to 112. Excluding the Speaker, that would leave a maximum of just 204 Tory MPs backing the deal, plus one Liberal Democrat and one Labour defector. The DUP has already said its 10 MPs will vote against the Government, and if they are joined by all Labour, Lib Dem, Scottish Nationalist, Green, Plaid Cymru and independent MPs, that would make 435 votes against the Government, a defeat of 229.
Mrs May is on course to outstrip the current record of a 166-vote defeat, suffered by Ramsay MacDonald in 1924.
Labour whips have told MPs to be ready for a no confidence vote with Mr Corbyn preparing to raise a point of order within minutes of the result being confirmed tonight.
The censure motion would take place after Prime Minister's Questions and could be limited to just 90 minutes of debate before MPs are asked to vote, according to a senior Labour source.
Should the censure motion secure the backing of a simple majority of MPs, it would almost certainly force Mrs May to resign and give the Conservative Party just two weeks to form an administration.
On Thursday, Mr Corbyn will then travel to Hastings, Work and Pensions Minister Amber Rudd's constituency, where he will speak at an event that will seen by many as a potential springboard from which to launch an election campaign.
The constituency is likely to become one of Labour's key target seats with Ms Rudd, a potential successor to Mrs May, wielding a wafer-thin majority of just 346.
This makes Ms Rudd vulnerable to a "decapitation" strategy that could see Labour throw vast resources at the constituency to unseat a possible future Tory leader.