Theresa May last night lost control of the Brexit process as MPs wrestled away the Parliamentary timetable from the Government.
The humiliating defeat means that MPs will stage a series of votes on an alternative way forward on Wednesday.
But the Prime Minister insisted she would not hand Parliament a “blank cheque” to decide what happens next.
A plan from senior Tory MP Sir Oliver Letwin was passed by 329 votes to 302 after 30 Tories rebelled.
Three of her ministers quit to vote for the plan, taking the total who have resigned over Brexit to 29.
One, business minister Richard Harrington, accused the PM of “playing roulette with the lives and livelihoods of the vast majority of people in this country”.
Shadow Brexit Secretary Sir Keir Starmer said: “It’s another humiliating defeat for a Prime Minister who has lost complete control of her party, her Cabinet and of the Brexit process. Parliament has fought back - and now has the chance to decide what happens next.”
Mrs May had come under mounting pressure to come up with a Plan B after her Brexit plans hit the buffers.
As the clock ticked down, she pulled a third vote on her doomed deal - but did not say when, or even if, it would take place.
And while she insisted that a damaging No Deal Brexit was off the table, No 10 officials then said it was not.
She faced more calls from Tory MPs to quit as her failure of leadership amid the greatest crisis in a generation infuriated MPs from across the Commons.
Even her own Cabinet ministers were left blindsided.
“It’s extraordinary that at this crucial stage we still don’t know what is going on,” one said.
The UK has been given until April 12 to agree a deal and then must either crash out of the EU or delay for an alternative plan.
Under Mr Letwin’s plan, MPs will take over the Parliamentary timetable from Wednesday afternoon, potentially for several days.
They will get a series of votes on the alternatives to Mrs May’s deal, such as a softer Brexit or a free trade agreement.
MPs could even legally instruct the Government to go back to Brussels with a new plan.
But Mrs May has not said she will accept the outcome.
“No Government could give a blank cheque to commit to an outcome without knowing what it is,” she said.
MPs will be asked to vote on a slip of paper at the end of the debate on the Brexit options.
Sir Oliver urged them to be prepared to compromise and sign up to all those they could live with.
“If we all vote just for our first preference we all know we will never get to a solution,” he said.
But Tory Brexiteer MPs attacked him for unleashing a “constitutional revolution” and accused him of being a “jobbing PM” with no accountability.
Labour MPs will not necessarily get a free vote on all the options, which could benefit those backing a softer Brexit.
The PM continues to oppose staying in a customs union as it would make the Tory party ungovernable.
But she met Jeremy Corbyn for “frank” talks yesterday on the way forward.
Beleaguered Mrs May has just 48 hours to finally get deal through under the timetable agreed with the EU.
She wants to plough on with her own plan even there were signs that opposition to it was now growing.
Her hopes suffered a blow when the DUP told her that they were still against it.
The support of the hardline Northern Irish MPs would bring large numbers of Tory rebels, including Jacob Rees-Mogg, with them.
With speculation swirling about her future, Mrs May told MPs that it was with “great regret” that she felt “as things stand” there was still not sufficient support to bring her deal back for a third vote.
She also infuriated hardline Brexiteers by telling them that their preferred No Deal exit was no longer an option.
This was because 318 MPs had already voted to oppose it. “Unless this House agrees to it, No Deal will not happen,” she told them.
Tory Brexiteer Crispin Blunt accused the PM of “shameful surrender” and suggested she had put “the final torpedo’ into her own plan
She further angered the DUP by suggesting No Deal would be so damaging for Northern Ireland, where devolved Government is suspended, that no PM could allow it.
But within moments of making her remarks, Downing Street officials were already rowing back. “The point the PM was making is that the House has voted against no deal, and will take every opportunity to prevent no deal,” one said.
MPs will tomorrow [WEDS] get a vote to delay Brexit Day to April 12, if a deal isn’t passed, or to May 22 if it is.
Mrs May hinted that a “slow Brexit” with a longer delay was on the cards if MPs did not back her deal.
Senior ministers have warned that a general election could be the most likely outcome of the impasse.
“It’s not just scare-mongering, it’s the only way out of this,” said one Government source.
However, No 10 insiders denied that was part of the PM’s plan.
Mrs May is under growing pressure to give a date for leaving office as the price of getting Brexiteers to fall into line.
Tory MP Nigel Evans said: “Clearly a number of people do not want the PM anywhere near the next phase of negotiations”.
Senior eurosceptics who visited the PM at Chequers over the weekend held more talks on whether she would have to go public.
The group have allegedly called themselves the ‘Grand Wizards’ apparently without having a clue that it refers to the Ku Klux Klan.