MPs voted Tuesday evening to take control of parliament’s business and pursue the passage of a cross-party bill to prevent the Conservative government of Prime Minister Boris Johnson from leaving the European Union (EU) without a trade and customs deal.

MPs backed the motion to allow a debate on the bill today by 328 votes to 301, a majority of 27. Twenty-one Tory MPs rebelled despite threats to withdraw the party whip and prevent them from standing for re-election for the party.

Responding to the defeat, Johnson said he would table a motion Wednesday for a vote on holding a general election before October 17—the final date that European Union (EU) leaders are able to agree a deal with the UK on its exit terms.

The emergency debate went ahead after the Speaker, John Bercow, allowed an application from Oliver Letwin, a fellow Tory Remainer. The bill sponsored by Labour Blairite Hilary Benn would force Johnson to request that the EU agree to delay Brexit until January 31, 2020 unless MPs had approved a new deal, or voted in favour of a no-deal exit, by October 19. It also mandates the EU to dictate further Brexit delays. Benn stated, “If the European Council agrees to an extension to the 31 January 2020, then the Prime Minister must immediately accept that extension. If the European Council proposes an extension to a different date then the Prime Minister must accept that extension within two days, unless the House of Commons rejects it.”

Taking control of parliamentary business and passing the bill was the response of the “Rebel Alliance” of opposition parties, led by the Labour Party, to Johnson’s authoritarian move last week to prorogue parliament from September 9, 10 or 11 for five weeks. Johnson did this as opposition MPs made clear they would oppose a no-deal Brexit in this session of parliament.

The representatives of the Remain wing of the ruling elite have been plotting how to prevent a no-deal Brexit since Johnson replaced Theresa May as prime minister in July. On Monday evening, Johnson in a televised address from Downing Street reiterated that there were “no circumstances in which I will ask Brussels to delay.”

The debate took place in extraordinary circumstances, with the Tories losing their working majority of just one MP—even as Johnson made a statement to Parliament prior to the emergency debate on last week’s G7 Summit. Tory MP and former Justice Minister Phillip Lee crossed the floor of the House to join the Liberal Democrats.

On Sunday, a senior source in the whips’ office said, “The whips are telling Conservative MPs today a very simple message—if they fail to vote with the government on Tuesday they will be destroying the government’s negotiating position and handing control of parliament to [Labour leader] Jeremy Corbyn… Any Conservative MP who does this will have the whip withdrawn and will not stand as a Conservative candidate in an election.”

Among those threatened are Ken Clarke, the pro-EU Father of the House (its longest serving member) who has been an MP since 1970, May’s former Chancellor Philip Hammond and even the grandson of Winston Churchill, Sir Nicholas Soames.

The concerns of the City of London were outlined by the Financial Times , which editorialised, “It will no doubt be painful for longtime Tory loyalists to go against Downing Street. Some may balk at potentially plunging the country into an election. They should keep in mind, however, that this week is surely the final chance to block a no-deal departure on October 31. However painful, they should put the national interest ahead of their careers and back Tuesday’s vote.”

Johnson’s threat of an early election requires a two thirds majority vote by MPs under the Fixed Term Parliament Act and will not be agreed. For months, Labour’s majority Blairite wing have insisted that there should be no general election until Brexit has been delayed. Capitulating, Corbyn abandoned his plan to call a no-confidence vote and appeal for support for him leading a caretaker government to stop a no-deal outcome and instead backed Benn’s bill.

In a speech at the Institute of Government on Monday, Tony Blair declared, “In backing away from the idea of himself as a ‘caretaker Prime Minister’ Jeremy Corbyn has behaved responsibly and if he continues to put country first, he will benefit the country and himself.” He insisted, “If the Government tries to force an election, Labour should vote against it."

Corbyn heeded his new master’s voice. On Tuesday, after talks with opposition party leaders, he reiterated that he would not call for a general election prior to legislation going through that would tie Johnson’s hands. Sean O’Grady, a columnist at the Remain-supporting Independent responded, “This is very much a principled move, in the national interest and (for a change) it is a Labour parliamentary manoeuvre that will succeed.” Last night, Corbyn immediately responded to Johnson’s move to call a vote on an early general election by saying he would not back such a call unless Benn’s bill ruling out a no-deal exit was passed first.

If the bill goes through Parliament today as expected, it will be speeded through for a further reading in the House of Lords tomorrow with the Remainers aim for it to be on the statute books prior to Parliament’s proroguing next week. The bill stipulates that if passed by the second chamber, MPs must make time for any Lords amendments to be debated in order that the bill is able to complete its passage. But so far 90 amendments have been put by pro-Brexit Tory peers. This might impact Johnson’s prorogation plans as Parliament will be prevented from being adjourned Monday, Tuesday or Wednesday next week until the Speaker has announced the bill has received Royal Assent and is an Act of Parliament.

This has led to speculation that Johnson will seek an alternative means of securing an election that only requires a simple majority, with the introduction of a one-line bill.

A general election can only worsen a crisis of rule unprecedented since the Second World War. Editorialising yesterday prior to the vote, the hard-Brexit-supporting Sun, owned by billionaire oligarch Rupert Murdoch, warned that a victory for the Remainers would mean Johnson “will have no choice but to reluctantly­ trigger a snap election.”

Corbyn has ensured that any election fought will be run as a de facto second referendum on Brexit instead of as a challenge to a reviled government set on imposing yet more austerity on working people. The Sun insisted that this was a contest that Johnson could win. Its message was that Brexit Party leader Nigel Farage—who is polling in double figures—must fall into line and back Johnson outright. “Voting for Nigel Farage will not deliver the No Deal exit they [Farage supporters] want. Unless he gets behind Boris to do so, he will split the Leave vote and probably gift power to a Marxist Labour Party now bent on reversing Brexit.”

Farage has mooted that if Johnson stuck to his no-deal pledge, he would be prepared to enter a non-aggression pact with the Tories in an election. The Sun gave prominence to research showing that Johnson could win up to 20 seats from Labour in the north and “hand the Tories a ‘net gain’ of 18 seats in the North as they lose five other marginals to the Liberal Democrats and Labour.