The SNP could “make life very difficult” for Labour after the next general election if Sir Keir Starmer does not co-operate with the party, Humza Yousaf has warned.

The First Minister said a demand for a second independence referendum would be “top of the list” of his party’s requests if Labour needs help forming a government at Westminster following the next general election.

It comes amid calls from Sir Keir for a snap general election to be held as the Conservatives face defending at least three Westminster by-elections following Boris Johnson quitting the Commons.

The Labour leader has repeatedly said he will not do a deal with the SNP after the election.

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Speaking on the BBC’s Sunday with Laura Kuenssberg show, Mr Yousaf said independence will be “front and centre” of the SNP’s general election campaign.

He spoke of his desire to grow support for independence, admitting that leaving the Union was not currently the “will of the Scottish people”.

The FM said: “I don’t want to be there or thereabouts, I want independence to be the consistent, settled will.

“At the moment, for example, it’s pretty obvious that independence is not the consistent, settled will of the Scottish people.”

Asked if it is realistic that Scotland will remain part of the UK for another five years, he said: “Not if I’ve got anything to do with it.”

The SNP leader also said he has recently spoken to his predecessor, former first minister Nicola Sturgeon, claiming she is “in a good place and doing well”.

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He added: “Why would I not want to get some advice from arguably one of the best politicians, the most impressive politicians, Europe has seen over the last couple of decades?”

On the general election expected to take place next year, Mr Yousaf said the SNP will not support a Tory minority government, but noted minority governments often need help passing budgets.

Mr Yousaf said: “We would never prop up a Conservative government, ever. Underline that, put that in bold.

“But, of course, if Labour do not want to co-operate with us, then we would make life very difficult for them.”

This could include on the legislative process and the passing of budgets, he said.

Deputy leader of Scottish Labour, Jackie Baillie, claimed Mr Yousaf has effectively admitted the SNP would "usher in a Tory government".

She added: “That threat is a betrayal to the people of Scotland, who are dealing with soaring living costs and falling wages.

“The next election is about getting rid of this morally bankrupt Conservative government, and delivering on Labour’s promise of lowering bills, strengthening worker’s rights and investing in the green jobs of the future.

“The SNP have made clear where their priorities lie and that’s to make life difficult for an incoming Labour government."

YouScottish Conservative chairman Craig Hoy, said Mr Yousaf’s remarks “confirmed that his party’s obsession with pushing for another divisive referendum will be put above the people's priorities”.

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He said: “Yet another SNP election campaign will seek to divide Scotland rather than focusing delivering on the real priorities of Scotland.

“Humza Yousaf is seeking to turn the general election into a de facto referendum, knowing fine well that people vote on a huge number of issues. All this comes at a time when the SNP leader admitted Scots do not back his plans to break up the United Kingdom.”

Mr Hoy added: “What is also clear is that the First Minister knows that if Keir Starmer needs the SNP’s help to get the keys to Number 10, the Labour leader will cave in to their demands for another divisive referendum.

“The First Minister also appears confident he could hold a minority Labour government to ransom on key legislation.”

The FM’s warning to Labour comes as Sir Keir urged Rishi Sunak to call a snap general election after three quick-fire MP resignations left the Prime Minister facing by-election battles on multiple fronts.

The Herald: UK Labour leader Sir Keir StarmerUK Labour leader Sir Keir Starmer (Image: PA)

Sir Keir Starmer said Mr Sunak “must finally find a backbone” and send the country to the polls after the Prime Minister found himself three MPs down in the space of 24 hours.

The call was echoed by Liberal Democrat leader Sir Ed Davey as rival parties hope to inflict more damaging by-election defeats on the Tories.

Nigel Adams on Saturday became the latest to announce he would be quitting as an MP with “immediate effect”.

An ally of Boris Johnson, he followed the former prime minister and former culture secretary Nadine Dorries in departing the green benches.

Mr Adams and Ms Dorries had been tipped for peerages in Mr Johnson’s resignation honours but neither featured in the published list.

Mr Johnson announced his exit on Friday as he directed a scathing attack on the Commons Privileges Committee probe into whether he misled MPs with his assurances over parties held in Downing Street during coronavirus lockdowns.

He compared the process, chaired by veteran Labour MP Harriet Harman but which has a Conservative majority, to a “kangaroo court” and accused the seven-person panel of being on a “witch hunt”.

In his lengthy statement, Mr Johnson appeared to keep the door open for a return to Parliament, saying he was leaving “for now”.