Scotland’s top law officer was not confident Holyrood has the powers to legislate for a new independence referendum.
Lord Advocate Dorothy Bain agreed to refer the matter to the Supreme Court after Nicola Sturgeon announced last month her intention to hold another vote.
Ministers were unable to say what legal advice they received before deciding to ask the court to opine on the issue rather than presenting a Bill to the Scottish Parliament.
But court papers show Ms Bain was not convinced MSPs have the powers required to legislate on the issue.
People ‘ought to have clarity’
In an 18-page reference document, the law chief sets out how she “needs to have the necessary degree of confidence that a Bill would be within devolved competence in order to ‘clear’ such a statement”.
She adds: “In the present case, the Lord Advocate does not have the necessary degree of confidence”.
Ms Bain says MSPs, ministers and people across the UK “ought to have clarity on the scope of the relevant reservations on this issue of fundamental constitutional importance”.
She adds: “Being questions of law, only this court can provide that clarity and unless the issue is judicially resolved there will remain uncertainty and scope for argument about the powers of the Scottish Parliament.
“That is not in the best interests of the people of Scotland or of the United Kingdom.”
Referendum result not legally binding
Ms Bain stresses any referendum held next year would not be legally binding but would simply indicate the will of the Scottish people.
“The Bill does not stipulate what should happen in response to the result,” she writes.
“The Bill provides only that the referendum should be held.
“Consequently, as a matter of law, the legal effect of a referendum held pursuant to the Bill would be nil.”
If the Supreme Court returns a verdict that even an indicative vote is not within the powers of the Scottish Parliament, the SNP plans to fight the next general election as a “de facto referendum” on the single issue of independence.
‘Hiding from scrutiny’
Scottish Conservative constitution spokesman Donald Cameron suggested the Lord Advocate’s lack of confidence in Holyrood’s powers is why she did not appear in front of MSPs before Parliament went into recess.
“Yet again we can see exactly what the SNP are up to – playing political games by going to court in order to stir up grievance,” he said.
Lib Dem MSP Willie Rennie said: “This publication arrives days too late for the MSPs to quiz the Lord Advocate on her proposals.
“It’s another example of a Scottish Government that is not confident in its own arguments and so chooses to hide from scrutiny.”
SNP MSP Neil Gray said: “There is a substantial majority in the Scottish Parliament in favour of an independence referendum and therefore a clear democratic mandate.
“However, as the first minister set out last week, there remains debate over whether the Scottish Parliament has the powers to legislate to hold a referendum.
“A Supreme Court decision on the matter seeks to accelerate us to the point that we have legal clarity.
“We hope that it will be deemed to be within the legislative competence of the Scottish Parliament. If that outcome is secured we will then introduce the Bill.”