Nicola Sturgeon last night defied accusations of stoking division by claiming that the Supreme Court’s verdict rejecting her right to call another independence referendum “has galvanised the Yes movement right across Scotland”.

The SNP leader and First Minister used an address to party colleagues and supporters at St Andrew’s night dinner in Glasgow to turn the argument into a battle for democratic rights.

She said: “The myth that the United Kingdom is a voluntary union of nations has been comprehensively – and permanently – shattered because of the behaviour of the Westminster parties. The so-called partnership of equals is anything but.

“Tory, Labour, Lib Dem — they’re all joined at the hip. They now have to defend the indefensible. If they thought that this outcome would be helpful to them, they have made a catastrophic miscalculation.”

Ms Sturgeon, who has now said she will turn the next General Election into a ‘de facto’ referendum, added: “The inconvenient truth for Westminster is that much as they would prefer otherwise, the Scottish independence movement is not going away.

“Indeed, it is growing. It is strengthening. And it is winning. Because it is now as much a democracy movement as an independence movement.”

She said the campaign for independence has changed “because  we are defending a universal, basic right – the right to make a democratic choice.

“Secondly the idea of the UK has been shown to have changed from a voluntary union to a Westminster control system.”

Her comments came amid growing appeals to tone down the rhetoric or risk stoking the flames of an already divided nation. She was recently slapped down for stating that she “detests the Tories”.

Following the Supreme Court verdict  she is now turning opponents of independence into deniers of democracy and is branding the UK as an unfair and unequal partnership.

However, her mandate for a referendum would be based on winning a majority of Westminster seats and this may not translate into winning a majority of the total vote which she would need in a referendum.

Scottish Labour leader Anas Sarwar, who says he will campaign around co-operation rather than conflict, said every politician should be careful about the language they use.

“Nicola Sturgeon is a division politician, I am a unity politician. She wants to create an us-versus-them across the country. She is an anger-driven politician, in the sense she wants to feed off anger and despair. I want to build an alliance across the country, I want to deliver empathy and hope to people,” he told The Times. 

Even one independence supporter who was due to attend last night’s dinner questioned whether the message was becoming more desperate than defiant, telling Daily Business: “We could even be seeing the end of the SNP.

“The court ruling has blown a big hole in the campaign and left us relying on a UK general election that will not change anything without Westminster’s say-so.”

Labour will lay out its new constitutional plan next month when the former party leader and Prime Minister Gordon Brown publishes his constitutional review.

The Yes movement was delivered a further blow last week by research that suggested a newly independent Scotland faces up to six decades of decline.

John Bryson, a professor of enterprise and economic geography at Birmingham University, used the track record of post-independence Ireland as a model for how Scotland would fare if it ever leaves the UK.

“The Scottish government should acknowledge that post-independence would involve a long adjustment period,” he wrote in an analysis of the recent Scottish government paper on a post-independence economy.

“I would suggest this should take between one or two generations, or between 30 and 60 years. These will be difficult years during which living standards and public service provision will decline as Scotland negotiates a new future with Britain and with other trading partners.

“Building a new Scotland will initially require fiscal restraint that will be reflected in a decline in public service provision.”