Boris Johnson on Tuesday night suffered a crushing defeat as Tory rebels joined forces with Labour and other opposition parties to seize control of the House of Commons agenda and derail his Brexit strategy.
The defeat clears the way for MPs to vote on Wednesday on emergency legislation which aims to prevent Mr Johnson from taking Britain out of the EU on October 31 without a deal. It could also herald a general election.
The prime minister said the legislation should be called “Jeremy Corbyn’s surrender bill”, because it would force him to go on bended knee to Brussels to seek an extension to the Article 50 exit process, with the EU laying down the terms.
What actually happened on Tuesday night?
The so-called “rebel alliance” of opposition MPs and anti-no-deal Tory MPs succeeded in taking control of the Commons order paper, allowing them to introduce a bill on Wednesday aimed at putting a legal block on a no-deal Brexit.
Mr Johnson lost by 328 to 301, a serious setback for a prime minister who tried to bully MPs into backing him. He warned rebels that if they did not back him, they would lose the whip and face deselection as Tory candidates at the next election.
He argues that unless the EU thinks he is serious about leaving the bloc whatever the circumstances on October 31, he will not be able to secure a better deal at the Brussels summit on October 17-18.
Will the anti-no-deal legislation become law?
The MPs of the “rebel alliance” should be able to turn their procedural victory on Tuesday night into a legislative triumph on Wednesday, when the bill to stop a no-deal Brexit is rushed through its Commons stages.
The bill, which would require Mr Johnson to seek a Brexit delay until January 31 if he cannot secure an exit deal in Brussels, will then head to the House of Lords, where it could face a more complicated passage.
Tory Eurosceptic peers could filibuster to try to delay passage of the bill but, ultimately, they are not expected to block a measure passed by the elected chamber. The bill would then, in normal circumstances, go to the Queen for royal assent.
Can the government do anything to stop it?
Mr Johnson repeated on Tuesday that he would never request a delay to Brexit, raising speculation that he might try all manner of tricks to stop the bill reaching the statute book, including refusing to send the bill to Balmoral for royal assent.
Tory rebels do not trust Mr Johnson or his adviser Dominic Cummings, who has promised to use “all necessary means” to deliver Brexit. But the prime minister insisted: “We will, of course, uphold the constitution and obey the law.”
One entirely constitutional option would be for Mr Johnson to seek an early election — the route he proposed last night — thus attempting to persuade MPs to agree a dissolution of parliament before the bill has become law.
Will Boris Johnson call an election?
That is what he threatened on Tuesday night, if MPs persist in pushing through their anti-no-deal legislation, in spite of insisting on the steps of Downing Street on Monday: “I don’t want an election, you don’t want an election.”
The prime minister would hold a poll on October 14 or 15, allowing him to seek a working Commons majority and then travel to Brussels for the EU summit to gain a better deal — or proceed to a no-deal exit if he cannot secure one.
The prime minister wants to trigger the election before the anti-no-deal legislation reaches the monarch at her Highland castle for royal assent. A five-week election campaign would immediately ensue.
Can he actually call an election?
Under the 2011 Fixed Term Parliaments act, Mr Johnson would need the support of two-thirds of MPs to trigger an early election. That would mean he needed the backing of Labour MPs to carry out his plan.
Labour and other opposition parties crucially want to put the anti-no-deal law on the statute book before a snap poll. Jeremy Corbyn also says he wants an election but he will seek cast-iron assurances from Mr Johnson that the poll will take place on October 14 or 15, well before Brexit day.
Labour fears that Mr Johnson, once he has secured a dissolution of parliament, could advise the Queen that the election be held after Brexit day on October 31. Downing Street has promised that would not happen — and says it legally could not happen.
Would Mr Johnson win an election?
The prime minister’s advisers believe that the Tories could “crunch Corbyn” in an election, which would see Mr Johnson present the Conservatives as the party of Brexit and the champions of “the will of the people”.
But Mr Johnson could not be sure of coming back with a Commons majority. While opinion polls suggest that he might take some seats from Labour in its Leave-voting heartlands, the Tories could lose seats elsewhere.
The Tories could lose most of their 13 seats in Remain-voting Scotland, could suffer defeats to the resurgent Liberal Democrats in the south, and Labour remains strong in big cities, including London. The election result would be highly uncertain.