A no confidence vote that could oust Theresa May will be held today after Jeremy Corbyn launched his attack seconds after the Brexit deal was crushed.
The Labour leader is seizing on the Brexit chaos to try to force the Tories out of power and get the keys to Number Ten for himself.
But braced for the attack, the PM told the Commons she would face a confidence vote before he had a chance to announce his plan.
Getting to his feet at the end of an explosive day in Parliament, Mr Corbyn said the PM had suffered a 'catastrophic' defeat that has left her Brexit plan in tatters.
In a defiant statement moments after Mrs May was defeated 432 to 202, Mr Corbyn said he had tabled the crucial motion.
He said: 'The result of tonight’s vote is the greatest defeat for a government since the 1920s in this House. This is a catastrophic defeat for this government.
'After two years of failed negotiations, the House of Commons has delivered its verdict on her Brexit deal and that verdict is absolutely decisive.'
His spokesman even suggested that if Labour lose tonight's vote they could table another no confidence vote in future weeks.
The move triggers a high-stakes contest that, if he wins, could send Mrs May tumbling from office and pave the way for a general election.
But Mrs May looks set to cling on tonight after the DUP and her hardline Brexiteers confirmed they would vote for her - despite pulling their support last night.
Jeremy Corbyn is hoping to seize on the chaos of the PM's deal being voted down to table a no confidence motion and try to topple Mrs May
Theresa May (pictured in the Commons last night after her crushing defeat) will face a fresh attack tonight as Labour try to topple her from power
Jeremy Corbyn (pictured leaving Parliament last night) said it was a 'catastrophic' defeat for the Government and confirmed he would seek to oust Mrs May tonight
Mr Corbyn had been under a huge amount of pressure from his MPs to table the vote to try to topple the PM after her humiliation last night.
He had threatened to hold the vote last month, but U-turned on it in a move which saw him mocked by his critics.
Backbencher Gavin Shuker said failure to force a vote would be an 'abdication of leadership' and prove that the Labour leader is just trying to dodge backing a second Brexit referendum.
What is a vote of no confidence?
To win and keep power, any Prime Minister has to be able to win votes in the House of Commons - this is known as 'confidence'. Where the Opposition believes this is no longer true, it can call a vote of no confidence to demonstrate it.
Why is Corbyn expected to call one tonight?
Theresa May is set to lose a vote on her Brexit deal tonight - potentially by the biggest margin ever recorded. Corbyn will say this is proof she does not have the confidence of the House.
Why might he delay?
Corbyn has resisted demands for weeks to call a vote, insisting it will only happen when he is sure he will win. His backbenchers think it is also to avoid him having to back a new referendum on Brexit.
How will he do it?
If he makes his move, Corbyn will appear briefly at the Despatch Box to make a point of order. He will announce he has tabled a motion of no confidence.
When will the vote happen?
Commons rules say the Government should schedule the motion for a debate and vote 'soon'. It is widely expected to happen tomorrow - but could be delayed until Thursday and maybe even Monday.
Will May lose?
Probably not - this time. Labour and other opposition parties cannot win without help from Tory MPs. Some have suggested they might join a no confidence motion to prevent no deal Brexit but May is unlikely to back this after losing tonight's vote.
What would losing mean?
Historically, losing a no confidence vote would be a trigger for the Prime Minister to resign and call a general election. This last happened in 1979, bringing down James Callaghan 311-310 - paving the way for the election of Margaret Thatcher.
This is no longer true. Instead, it starts a 14-day countdown in which the Government must assemble a new coalition or the Opposition must demonstrate it can form a Government.
Failure would then mean an election.
Mr Shuker said yesterday: 'A failure to table a no confidence motion would be a huge betrayal tonight.
'An abdication of leadership; the act of someone trying dodge a People's Vote and run down the clock.'
Labour want to oust Mrs May, force a general election, seize power and take control of the Brexit talks.
They insist that a Labour government would do a better job in the talks than the PM.
But Labour are deeply divided on Brexit - with many Remainer MPs clamouring for a second referendum while voters in the Labour heartlands overwhelmingly backed Brexit.
Mr Corbyn is under
