NICOLA Sturgeon has insisted that the “common sense” option of the UK staying in the single market and customs union is probably the only one that can now command a Commons majority as she claimed the case for Scottish independence had “strengthened immeasurably” since 2014.

The First Minister argued that the take-it-or-leave-it Brexit deal Theresa May was offering was not credible; there were alternatives to her unworkable Chequers Plan.

“They are threatening us with fire to try to make us choose the frying pan but MPs do not have to fall for that false choice. Indeed, I would argue that no self-respecting Parliament would fall for it,” she declared.

In a speech to the Royal Society of Arts, the social change think-tank, in London, Ms Sturgeon complained that the Conservative Government had shown “little inclination to pay heed to Scotland” during the Brexit process.

“One of the lessons from our experience of the last two years, which I suspect has not been lost on the Scottish people and which will be remembered in Scotland for a long time to come, is the stark contrast between the EU’s treatment of independent nations and the UK’s treatment of devolved nations.”

Claiming the UK had “dismissed and ignored” Scotland’s concerns, the FM noted: “Looking at the UK and the EU, it is fair to say that only one has looked like a genuine partnership of equals; and that has not been the UK.”

Ms Sturgeon stressed how her Government had made a “big compromise” by dropping its demand that Scotland remain in the EU and pledged it to exhausting all the “opportunities for compromise,” holding out hope that a sensible outcome could be achieved. However, she made clear Scotland staying in the customs union and single market was Edinburgh’s “bottom line”.

She pointed out that if there were a special carve-out on the single market for Northern Ireland, then Scotland should be next in line for a “differentiated approach”.

The FM only fleetingly mentioned the option of a second independence referendum, saying how if no compromise could be reached, then Scotland “must have the option to choose a different course” ie independence.

In a question and answer session following her speech, she claimed the “case for democratic independence since 2014 has strengthened immeasurably,” noting how in the referendum campaign it was argued a Yes vote would result in Scotland leaving the EU.

“That brings into sharp focus the democratic deficit Scotland has experienced on many occasions, which on this issue it has felt particularly harshly,” she said.

The Nationalist leader dismissed the Prime Minister’s compromise blueprint as “impracticable, undesirable and undeliverable,” stressing that whatever proposal MPs might finally vote on, it would not be the Chequers Plan.

She noted how the EU was bitterly opposed to Chequers because it would undermine the unity of the single market, dealing only with goods and not services. Plus, there was no Westminster majority for it.

Ms Sturgeon rebuffed Mrs May’s claim that it was the only option on the table; this was so, the FM pointed out, because the PM refused to countenance any other.

“Let’s be clear,” she declared, “a head-in-the-sand approach won’t make the Chequers ostrich fly.”

The SNP leader insisted that neither a fudged Brexit deal not a “blindfold Brexit” ie a vague political statement of intent about the UK’s future relationship with the EU, would do.  

A blindfold Brexit would “replace a no-deal Brexit with a no-detail Brexit,” she said.

“Voting against a bad or a blindfold Brexit deal isn’t a vote for no-deal; it would be a vote for a better deal,” insisted Ms Sturgeon.

The FM accused the Conservative Government of taking an “extreme interpretation” of the 2016 referendum result, which, she argued, was not a mandate for a hard Brexit and that the “obvious democratic compromise” was for the UK to stay in the single market and customs union.

Indeed, Ms Sturgeon went on to say that her preferred option “might well be the only option which is not completely impossible”.

She explained: “It should be acceptable to the EU. It avoids the worst economic damage that Brexit will wreak. It resolves the Irish border issue and it comes closest to reconciling the differing views of Leavers and Remainers. And while it is an outcome, which still looks some distance away, it is not unachievable.”

The FM called for a genuine attempt to find common ground, stressing how the Scottish Government had shown its willingness to compromise, “it is time the UK Government did likewise”.

In response, a spokesman for the Department for Exiting the European Union said: "We will have an ambitious course outside of the EU that enhances our prosperity and security and that genuinely works for everyone across the UK.

"We have put forward a precise and credible plan for our future relationship with the EU and look forward to continuing to engage with the EU Commission on our proposals."

Adam Tomkins, the Scottish Conservative Constitution spokesman, said there was "nothing new" in Ms Sturgeon's speech, which had been made "in the hope of drumming up the prospects for Scottish independence".

He added: "If the SNP doesn't back a deal, it is automatically supporting a no-deal scenario; something the Nationalists have admitted would be bad for Scotland.

"And, of course, they don't care if outcomes are bad for Scotland, so long as they're good for the prospects of another independence referendum."

Labour's Ian Murray, who co-chairs Scottish Labour for the Single Market, said: “There is no such thing as a good Brexit and the First Minister is right to state that UK membership of the single market and the customs union is the least-worst option for our economy.

“Given the problems with solving the border issue in Ireland, this is the only practical solution. It will also safeguard up to 80,000 jobs in Scotland.

“However, the SNP must not use the Brexit chaos to pursue its dream of breaking-up Britain. Nicola Sturgeon's suggestion of a differential deal for Scotland would move the Northern Irish problem to the border between Scotland and England. You can't solve one problem by creating another - but we know this is part of the SNP's drive for independence.

“Voters don’t want political game-playing from either the Tories or the SNP; they want this Brexit disaster to be dealt with,” added the Edinburgh MP.