Boris Johnson set for second crushing defeat on bid for early general election

Boris Johnson is heading for a second crushing defeat over the triggering of an October general election, as the SNP – and more Labour MPs – swung behind a plan to make him wait to “let the Tories unravel”.

Another Commons vote will take place on Monday, but the Scottish Nationalists signalled they will oppose a snap poll, making it more likely Jeremy Corbyn will do the same to maintain a united opposition.

Crucially, the motion will again be under the Fixed-term Parliaments Act, which means it does not tie down the election date – a key demand of the opposition parties – although the prime minister insisted it would be on 15 October.

The Labour figures who are pressing their leader to block an election until a Brexit delay has been agreed by the EU – delaying the poll until November, or later – received a boost from John McDonnell, Mr Corbyn’s key ally.

The shadow chancellor said Labour was “taking legal advice” on how to box in the prime minister and is “consulting about whether it’s better to go long, rather than to go short”.

Nicola Sturgeon had called for a quick election, but faced a backlash from senior SNP MPs, who instead made clear they favoured waiting until an Article 50 extension has been signed and sealed.

Pete Wishart, her constitution spokesperson, said: “His general election is coming, but everybody has to be certain that their no deal is dead and buried.”

The shifts came on another calamitous day for Mr Johnson, as his own brother quit in protest at his leadership – and a woman police officer collapsed behind him as he made a stump speech in Yorkshire.

The prime minister gave his opponents added incentive to keep him in office long enough for the humiliation of being sent to Brussels to stop a no deal, when he vowed: “I would rather be dead in a ditch.”

Clive Lewis, a Labour Treasury spokesperson, summed up his party’s mood, tweeting: “As Jo Johnson’s resignation demonstrates, every day his brother is boxed-in his problems multiply.

“Let’s secure the extension, let the Tories unravel, then open the gates, ride out & finish off what’s left. Always fight on the ground & time of your own choosing, not your opponents.”

Two-thirds of MPs must vote in favour to overturn the Fixed-term Parliaments Act, meaning Mr Johnson needs the help of his opponents to reach the magic figure of 434. But the Liberal Democrats, Plaid Cymru and the Greens also favour delay.

He could introduce a one-line bill to bypass the act, but this could be amended – and would force him to delay his controversial plans to prorogue parliament for five weeks from early next week.

Talks between the opposition parties on how to handle Monday’s vote will continue on Friday – but with Labour MPs lining up to defy any order to back an October election.

Stoke’s Ruth Smeeth, a supporter of a Brexit deal, said: “I don’t trust this prime minister to stick to his word on when that date would be.”

And Anna Turley MP, a northeast Final Say supporter, said: “I won’t be voting for a general election until Brexit is sorted after 31 October.”

But some of Mr Corbyn’s closest aides, and union leaders, favour an election as soon as possible – and some Labour MPs fear a decision made in the leader’s office.

“They might stitch it up over the weekend, when the rest of us are not around,” one shadow minister told The Independent.

And another warned. “Normally it will be up to the shadow cabinet to decide, but it won’t meet until Tuesday – so it could be the leader’s office making that decision.”

The cross-party bill to force a further three-month Brexit extension, if no deal has been struck by 19 October, will become law on Monday, after the government threw in the towel in the House of Lords.

In Wakefield, asked if he could promise not to return to Brussels to ask for a further delay, even if the law says he must, Mr Johnson said: “Yes, I can. I would rather be dead in a ditch.”

But he ducked the question of whether he would resign first, saying only: “What on earth is the point of further delay? I think it’s totally, totally pointless.”

Giving evidence to a committee of MPs, Michael Gove, in charge of no-deal planning, insisted the government would obey the law, if ordered to beg for the extension – but could not explain how, given his leader’s staunch refusal.