ITV News Scotland Correspondent Peter Smith reports on the political fallout from Nicola Sturgeon proposing a date for another independence referendum next year
She told the Scottish Parliament today that the question to be asked would be the same as in the 2014 vote "Should Scotland be an independent country?"
Ms Sturgeon said she would be writing to Prime Minister Boris Johnson to inform him of her plans.
She added she would make clear she is "ready and willing" to negotiate the terms of a Section 30 order with him, which would give Holyrood the power to hold a referendum.
With the prime minister having repeatedly refused her calls for another referendum to be held, Ms Sturgeon added: "What I am not willing to do, what I will never do is allow Scottish democracy to be a prisoner of Boris Johnson or any prime minister."
The first minister stated: "My determination is to secure a process that allows the people of Scotland, whether yes, no or yet to be decided, to express their views in a legal, constitutional referendum so the majority view can be established fairly and democratically.
"The steps I am setting out today seek to achieve that."
She told MSPs that should the government at Westminster not agree to a referendum she wanted to hold a legal referendum using legislation passed at Holyrood.
The Advocate General - Dorothy Bain, Scotland's leading law officer - is referring this matter to the Supreme Court with a view to establishing whether this is permissible under law. Ms Sturgeon said the process was already underway and "will be filed with the Supreme Court this afternoon."
Opposition MSPs laughed after she said: "It is of course possible that the Supreme Court will decide that the Scottish Parliament does not have power to legislate, even for a consultative referendum.
"To be clear, if that happens, it will be the fault of Westminster legislation, not the court."
She said if such a judgment is issued, then "any notion of the UK as a voluntary union of nations is a fiction."
Ms Sturgeon said that should it be proved that this cannot happen, the SNP would fight the next general election as a "de facto referendum."
A former Supreme Court Justice has said the Scottish first minister is charting “a very difficult course” after she unveiled plans to hold a second referendum on Scotland’s place in the United Kingdom next year.
Lord Sumption told BBC Radio 4’s PM programme: “It’s actually a very difficult course that Nicola Sturgeon has charted for herself.
“To have a referendum you need legislation. She accepts that and she wants to put a Bill through the Scottish Parliament.
“The problem is that constitutional relationship between England and Scotland is a reserved matter under the Scotland Act, which means that the Scottish Parliament has no power to legislate for anything that affects the constitutional relationship between two parts of the United Kingdom.”
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The UK government says the constitution is reserved to Westminster, meaning Holyrood cannot organise a vote on its own.
Lord Sumption said the Supreme Court would decide the matter based on the relevant law, not politics.
“The idea that the Supreme Court is going to make a political decision based on their views about Scottish independence is, I think, completely wrong.”
Nicola Sturgeon said it was a "matter of principle" that any referendum would be a legal ballot.
Outlining her bid to have an "indisputably legal referendum" she told MSPs at Holyrood the vote would be held "to ascertain the views of the people of Scotland as to whether or not Scotland should be an independent country."
She said this would be a consultative referendum as the vote on Brexit was in 2016.
As a result she explained a majority vote would not by itself make Scotland independent, adding and that legislation would have to be passed by the UK and Scottish Parliaments."
The First Minister concluded her speech by saying: "With hard work and the independence to chart our own course, Scotland will prosper, and the people of Scotland have told us, all of us in this chamber, that they want the right to decide."
Douglas Ross, the leader of the Scottish Conservatives, the largest opposition party at Holyrood, said Ms Sturgeon had "taken her eye off the ball".
“The real priorities of people across Scotland are on the back burner. Instead, the First Minister is putting her plans to divide Scotland front and centre," he told MSPs.
“Nicola Sturgeon has shown again today that the SNP’s selfish obsession with another divisive referendum is always their top priority. She will use government time and resources to further her plan to break up the country, just when we need to be pulling together and working as one."
Mr Ross added: “A potentially illegal referendum next year is the wrong priority for Scotland. It would distract attention away from our recovery. It will damage efforts to rebuild our country after Covid. It is the last thing a clear majority of Scottish people want."
He also said "we won't take part in a pretend poll" and accused Ms Sturgeon or presiding over a "do-nothing parliament".
Scottish Labour leader Anas Sarwar said: "The pandemic Nicola who said she wants to pull us through and the partisan Nicola Sturgeon is back."
Mr Johnson said he would study Ms Sturgeon's plans for a second referendum but "the focus of the country should be on building a stronger economy".
"I haven't seen exactly what she's said yet," he told reporters as he travelled to Madrid for the Nato summit. "We will study it very carefully and we will respond properly.
"The focus of the country should be on building a stronger economy, that's what we're doing with our plan for a stronger economy and I certainly think that we'll be able to have a stronger economy and a stronger country together."
Earlier today, Mr Johnson refused to rule out another referendum.
When asked he said: "Our plan for a stronger economy works better when the UK is together than when it is not together."
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