Prime Minister Theresa May’s Brexit deal has been rejected by 230 votes – the largest defeat for a sitting government in history.
MPs’ voted by 432 votes to 202 to reject the deal, which sets out the terms of Britain’s exit from the EU on 29 March.
Labour leader Jeremy Corbyn has now tabled a vote of no confidence in the government, which could trigger a general election.
The confidence vote is expected to be held at about 1900 GMT on Wednesday.
The defeat is a huge blow for Mrs. May, who has spent more than two years hammering out a deal with the EU.
The plan was aimed at bringing about an orderly departure from the EU on 29 March, and setting up a 21-month transition period to negotiate a free trade deal.
The vote was originally due to take place in December, but Mrs May delayed it to try and win the support of more MPs’.
The UK is still on course to leave on 29 March but the defeat throws the manner of that departure – and the timing of it – into further doubt.
MPs’ who want either a further referendum, a softer version of the Brexit proposed by Mrs. May, to stop Brexit altogether or to leave without a deal, will ramp up their efforts to get what they want, as a weakened PM offered to listen to their arguments.
In her statement to MPs’, Mrs. May said she planned to return to the Commons next Monday with an alternative plan – if she survives the confidence vote.
She said she would explore any ideas from cross-party talks with the EU, but she remained committed to delivering on the result of the 2016 referendum.
But European Commission President Jean-Claude Juncker said the risk of a disorderly Brexit had increased as a result of the deal being voted down.
He said the agreement was “the only way to ensure an orderly withdrawal” and that he and President of the European Council, Donald Tusk, had “demonstrated goodwill” with additional clarifications this week to put MPs minds at rest.
“I urge the United Kingdom to clarify its intentions as soon as possible,” he said. “Time is almost up.”
Mr. Tusk said he regretted the outcome of the vote and later tweeted to ask “who will finally have the courage to say what the only positive solution is?”
If a deal is impossible, and no one wants no deal, then who will finally have the courage to say what the only positive solution is?
— Donald Tusk (@eucopresident) 15 January 2019
A statement from the Irish government also said it regretted the decision and that it “continues to believe that ratification of this agreement is the best way to ensure an orderly withdrawal of the UK”.
It also said it will “continue to intensify preparations” for a no deal Brexit.
