IT IS “highly likely” Scotland will be asked to vote on independence before 2020, Nicola Sturgeon has said.

Speaking on ITV’s Peston show, the First Minister challenged Theresa May to stop the breakup of the UK by listening to the Scottish Government’s demands to remain in the European single market.

During last week’s SNP conference Sturgeon said she would soon publish a package of proposals for new powers on immigration and international deals for Holyrood, which would be the base for Holyrood-Westminster negotiations on Brexit.

If those discussions break down then a second independence referendum would seem inevitable.

“I think it’s highly likely, given the situation we’re in. I said that the morning after the EU referendum and nothing has changed my mind,” Sturgeon told Robert Peston.

“If anything, what’s happened since then has probably made me think that even more so than I did the morning after the referendum.

“That’s not to say that I am not absolutely serious about trying to explore all these other options – I am.

“But we have to see the Prime Minister be serious about listening to those other options, because if Scotland really is – as we’ve been told, repeatedly – an equal partner in the UK, [and] Theresa May is serious about protecting the UK, then it’s time for her to turn those words into action and actually demonstrate that Scotland’s voice is heard and our interests can be protected within the UK.

“We’ve not seen much of that from the Prime Minister so far, so I hope we see more of it in the weeks to come.”

Earlier, Sturgeon had told the BBC’s Andrew Marr, that the Prime Minister was “not fully honouring” promises to listen to Scotland.

“There’s a fundamental principle here – does Scotland’s voice matter? Does what we say, how we vote, how we think, count for anything?”

She added: “The House of Commons and the wider public has almost been told to butt out and mind their own business, and we saw in the House of Commons last week there’s not a lot of support for that kind of approach.”

SNP leader at Westminster Angus Robertson made clear that if May rolled back on hard Brexit and agreed to the Scottish Government proposals there would be no second referendum.

“If the Scottish Government is satisfied then I don’t see how the Scottish Government would pursue a further independence referendum,” he told the BBC’s Sunday Politics Scotland show. “Having said that, given that all the straws in the wind show the UK Government has not taken it seriously thus far, it is exactly why it is right and proper for the Scottish Government to begin consultation on an independence referendum just in case the UK Government does not deliver.”

Meanwhile, ahead of this week’s publication of an Independence Referendum Bill, Tory Scottish secretary, David Mundell, conceded that there could be another independence vote, but warned the SNP politicians that there would be no poll without May’s permission.

“Of course there could be another referendum, but we want to argue that there shouldn’t be another referendum,” he said. “We believe that the decision has been made and that it is now in Scotland’s best interests that the two governments work together in a ‘Team UK’ approach to get the best possible deal for Scotland in the EU.”

The Scots Tory minister also criticised the SNP for not having any post-Brexit plans. “We’ve had four months. No specific proposals have come forward,” he said. “Nicola Sturgeon’s this morning talking about having proposals, but I see it impossible that Scotland could remain within the EU while the rest of the UK left.”