Nicola Sturgeon said she will turn the next UK general election into a “de facto” referendum on Scottish independence following the Supreme Court’s decision that she cannot call one without Westminster’s consent.

The SNP leader said that although she was disappointed she respected and accepted the ruling, but she would look at other ways to hold the poll she has promised to deliver on 19 October next year.

“In securing Scotland’s independence we will always be guided by a commitment to democracy and respect for the rule of law,” she said.

“What I will not do is go cap in hand. 

“My expectation, in the short term at least, is that the UK government will maintain its position of democracy denial.  That position is, in my view, not just unsustainable – it is also utterly self-defeating.

“The more contempt the Westminster establishment shows for Scottish democracy, the more certain it is that Scotland will vote Yes when the choice does come to be made.

“We must, and will, find another democratic, lawful and constitutional means by which the Scottish people can express their will. In my view, that can only be an election.

“The next national election scheduled for Scotland is the UK General Election, making it both the first and the most obvious opportunity to seek what I described back in June as a de facto referendum. 

“I can therefore confirm that I will be asking our National Executive Committee to convene a special party conference in the new year to discuss and agree the detail of a proposed de facto referendum.”

Struan Stevenson, CEO of pro-union business group SBUK, said:  “Today’s decision from the Supreme Court is positive news for the Scottish economy because it signals to ministers at Holyrood that they are running out of options in their latest beleaguered referendum campaign.  

“Pressing on now would be an utter distraction at a time when business needs government laser-focused on working with companies to create the conditions for growth, as well as working hard to sustain Scotland’s vital infrastructure and public services.” 

The Supreme Court unanimously ruled that Holyrood does not have the power to bring forward legislation for a second poll.

President Lord Reed said the question of sovereignty was ‘reserved’ to the UK government.   

The Supreme Court is the highest court in the UK and there is no route to appeal, meaning it is the end of the legal route for Ms Sturgeon.

More demonstrations by independence supporters are expected to take place following the court’s verdict.

Lord Reed rejected comparisons with Quebec’s efforts to hold a referendum.

Delivering the verdict at 9.45am, he said: “The court unanimously concludes that the proposed bill does relate to reserved matters,” he said. “The Scottish Parliament does not have the power to legislate for a referendum on Scottish independence.”

He added: “A lawfully-held referendum would have important political consequences relation to the Union and the United Kingdom Parliament.

“Its outcome would possess the authority, in a constitution and political culture founded upon democracy, of a democratic expression of the view of the Scottish electorate.

“It would either strengthen or weaken the democratic legitimacy of the Union and of the United Kingdom Parliament’s sovereignty over Scotland, depending on which view prevailed, and would either support or undermine the democratic credentials of the independence movement.

“It is therefore clear that the proposed bill has more than a loose or consequential connection with the reserved matters of the Union of Scotland and England, and the sovereignty of the United Kingdom Parliament.”

In October Lord Reed warned it would be “some months” before the judgment was handed down.

However, he said today that a decision had been reached much earlier than expected because the judges were unanimous and had prioritised the importance of the case. 

The ruling means the Scottish Government’s top law officer, Lord Advocate Dorothy Bain KC, will not be able to clear the Bill for passage through the Scottish Parliament.