Nicola Sturgeon has said the Labour Party would have “questions to answer” if they do not accept the SNP’s post-election demands.

Speaking on the BBC’s Andrew Marr Show on Sunday, the First Minister warned senior Labour figures about rejecting negotiations with her party, which could risk putting Boris Johnson back into Downing Street in the event of a hung parliament.

Ms Sturgeon has previously set out “red lines” for SNP support, including an end to austerity, the scrapping of Trident and a second independence referendum.

Ms Sturgeon said: “We won’t put the Conservatives into government, but Labour would then have to get support to get their policies through.

“I would be offering that support.

“I don’t believe Labour, if against all the odds and what the opinion polls say, they get into a position to govern and implement their manifesto, they would turn their backs on that.

“My view here is that they should think about that prospect and imagine that on Friday Jeremy Corbyn and John McDonnell are in a position of being able to form a government, I don’t think they’re going to turn their backs on that.

“If they do, I think they’ve got some big explaining to do.”

Sturgeon Marr interview
The First Minister was speaking on the BBC’s Andrew Marr Show on Sunday (BBC/PA)

The First Minister said it was not imperative that Labour leadership support independence, or even another referendum, but she called on them “respect the principle” of self-determination.

“I’m not asking Labour to support independence, I’m not even asking Labour to think there should be a second independence referendum, I’m making the reasonable request that they respect the principle, which is if there is a referendum and the timing of that referendum should not be matters for Westminster, it should be for the Scottish people and parliament to decide.”

Speaking in the Sunday Mail, the First Minister asked for people who are against independence to vote for her party, saying their ballot does not mean they also support another referendum.

She said: “My message to them is that I don’t take their support for the SNP as necessarily support for independence.

“This election will not decide independence, it is about stopping Brexit and stopping Boris Johnson, it is about making sure the future of the country is decided here in Scotland, and I think that should be a point of unity.

“It is for the people to decide – they shouldn’t have that imposed on them.”

Labour candidate for Glasgow North East Paul Sweeney, speaking on Sunday Politics Scotland, said the Labour Party would not “stand in the way” of a second referendum if independence-supporting parties return a majority to Holyrood in 2021.

Ross Thomson groping allegations
The Labour candidate said any UK Government could not stand in the way of another independence referendum parties in favour won a majority in Holyrood in 2021 (Nick Ansell/PA)

Mr Sweeney added: “Ultimately, we’re democrats. We respect the right of the Scottish people to self-determination.

“If there were an explicit mandate for that, say, after the Scottish elections in 2021, it wouldn’t be for any British government to stand in the way of that.”

However, Mr Sweeney said there was no clear mandate currently for a second poll and his party “would not be going into that at this stage”.

Scottish Tory leader Jackson Carlaw said Mr Sweeney’s comments were confirmation of a deal between the two parties.

He said: “Paul Sweeney has set it out in black and white. A Labour–SNP pact is being drawn up; it’s just a matter of dotting the i’s and crossing the t’s.

“This is what could happen by Friday if Sturgeon and Corbyn succeed.

“It means our Union is on the line this week. Ian Blackford said today that he and Jeremy Corbyn speak regularly, and he doesn’t expect Corbyn to oppose the Nationalists.

“So pro-UK voters in Scotland face the very real risk of an Indyref2 pact being stitched up by the end of this week.

“Pro-UK voters in Scotland must act on Thursday to stop this happening. And it is only by voting Scottish Conservative and Unionist that we can do that.”

Mr Sweeney said there had not been any meetings between leaders of the two parties, however Ian Blackford said he would “meet regularly” with Jeremy Corbyn when parliament was sitting.

Liberal Democrat candidate Christine Jardine said her party would “not put Jeremy Corbyn into Downing Street, full stop”.

However, Ms Jardine did concede her party would back legislation for another Brexit referendum.