UK Prime Minister Theresa May’s proposed Brexit withdrawal agreement has failed to pass a vote in Parliament with an historically high loss of 432 votes to 202.

After five days of spirited debate – and one adjournment from December, when the vote was initially scheduled but was postponed by May after it became obvious that the Brexit withdrawal agreement would not pass through Parliament in its current form – the deal, which garnered criticism from all sides of the Brexit debate, has been enthusiastically rejected by MPs. The House of Lords voted last night to reject May’s deal by a majority of 321 to 152.

Earlier today Speaker of the House of Commons John Bercow selected four amendments to be voted on in tandem with the main Brexit withdrawal agreement, but three were later withdrawn; leaving only Amendment F, tabled by Conservative MP John Baron, which would give the UK the right to terminate the Northern Ireland backstop agreement unilaterally, without EU input. The amendment failed to pass the vote, with 24 MPs voting Aye and 600 voting No.

Under the terms of the Grieve amendment, May’s government now has three days to present a “Plan B” alternative proposal to the House of Commons; although the EU has made it clear they have no plans to renegotiate the Brexit withdrawal agreement. Increasing numbers of MPs and members of the public have called for a second referendum, on the basis that the results of the 2016 referendum which resulted in the UK’s decision to leave the EU were irrevocably tainted by corruption, inaccurate representation and a lack of cohesion on the part of Leave voters as to the terms on which they wanted to leave.

Large screens were erected in Parliament Square to enable activists and campaigners to watch the debate and subsequent vote live. Labour MP Tulip Siddiq rescheduled a planned caesarean section in order to vote against the Brexit withdrawal agreement, eschewing the House of Commons’s trust-based system of “pairing” MPs who could not attend votes with opposing MPs who pledged not to vote after the pairing system was abused in a previous session. Siddiq, who is undergoing a risky pregnancy, was wheeled into the House of Commons in a wheelchair.

It has been reported that MEPs would be prepared to extend Article 50, which currently commits the UK to leaving the EU with or without a deal on 29 March 2019, in order to allow the UK Parliament more time to come to an agreement on either the terms of a Brexit withdrawal agreement, a second referendum, or a majority vote for a no deal Brexit – although the last option has been roundly condemned by most Remain- and Leave-supporting MPs. However if Article 50 were to be extended, there would be a possibility that the UK would still be part of the EU for the European Parliament elections in May 2019; in which case under current terms UK MEPs would still be able to stand for election and take their seats, even though they may not be members of the EU by the end of the parliamentary term.

The failure of the Brexit withdrawal agreement represents the greatest loss for a British government, breaking the previous record of 166 votes in 1924, when the minority Labour government lost the vote over an amendment put forward by the Liberal party to establish a select committee to investigate the government’s decision to drop criminal charges against newspaper editor JR Campbell. In the aftermath of that historic loss, then-Prime Minister Ramsay MacDonald dissolved parliament and called a general election, which Labour promptly lost.

The pound is expected to drop in value in the wake of the government’s 230-vote loss. Before the vote party representatives let it be known that May could face calls to stand down if her Brexit withdrawal agreement lost by more than 200 votes; although, as the Prime Minister survived a vote of no confidence from her party in December, the Conservatives now cannot attempt to force her to resign as leader until December 2019. However if, as has been suggested, Leader of the Opposition Jeremy Corbyn calls for a vote of no confidence and the government loses, May will have to step down as Prime Minister. If a Prime Minister cannot then be found who can command a majority vote in the House of Commons within 14 days, a general election will be triggered.

The Prime Minister told MPs “the House has spoken and the government will listen.” Corbyn has tabled a motion of no confidence to be debated tomorrow.