The EU has called an emergency summit for 10 April after Theresa May's Brexit deal was defeated for the third time.
European Council president Donald Tusk called an emergency summit of EU leaders in Brussels on April 10 to discuss the implications of the vote.
Mr Tusk said: "In view of the rejection of the Withdrawal Agreement by the House of Commons, I have decided to call a European Council on 10 April."
Mrs May now has until April 12 to go back to Brussels with new proposals and seek a longer extension to the negotiation process, or see the UK leave without a deal that day.
European Commission secretary general Martin Selmayr tweeted: "12 April is now
the new 29 March."
With a clear majority in the Commons against no-deal, and with MPs once more seizing control of the timetable on Monday, Mrs May said that the UK would have to find "an alternative way forward".
This was "almost certain" to involve the UK having to stage elections to the European Parliament in May, she said.
Mrs May said that the outcome was "a matter of profound regret"
Labour leader Jeremy Corbyn called for a general election unless the Prime Minister was willing to find an alternative deal.
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And Mrs May - who had promised to step down as Prime Minister if her deal was approved - appeared to hint that this was a possibility, telling MPs: "I fear we are reaching the limits of this process in this House."
She said: "This House has rejected no deal. It has rejected no Brexit. On Wednesday it rejected all the variations of the deal on the table.
"And today it has rejected approving the Withdrawal Agreement alone and continuing a process on the future.
"This Government will continue to press the case for the orderly Brexit that the result of the referendum demands."
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Mr Corbyn told MPs: "The House has been clear this deal now has to change, there has to be an alternative found.
"And if the Prime Minister can't accept that then she must go - not at an indeterminate date in the future but now, so that we can decide the future of this country through a general election."
