Dorothy Bain QC has now published the letter she wrote to the UK’s highest court last week asking for its ruling on whether Sturgeon has the legal powers to hold a referendum without the UK government’s authority. Bain told the court she must approve a declaration from Scottish ministers when they table a new bill that it is legislatively competent under Holyrood’s devolved powers. “The lord advocate must have the necessary degree of confidence that a bill will fall within the exclusive competence in order to ‘clear’ such a statement,” he told the high court. “In the present case, the lead counsel does not have the necessary degree of confidence.” Her admission confirms widespread suspicions in Holyrood that Bain told Sturgeon that holding an independence referendum without permission from Westminster under the so-called section 30 order was likely to be illegal. Boris Johnson has repeatedly said he will not give that order. Sturgeon revealed last week that she wants the powers to hold a referendum without it, despite a major legal opinion that only Westminster can pass legislation affecting the UK constitution. The Lord Advocate’s letter reveals that the Scottish Government believes a referendum bill under Holyrood could be legal because it would be advisory only and would have no legal force and would ask a neutral question: “Should Scotland is it an independent nation?’ He told the court: “The Scottish Government accepts that an act of dissolution of the union does not fall within the legislative competence of the Scottish Parliament. However, it does not necessarily follow that the proposed bill, which provides for an advisory referendum on independence, is related to cautious issues. Subscribe to First Edition, our free daily newsletter – every morning at 7am. BST “[Given] the advisory nature of the proposed referendum, it is doubtful whether the proposed question (or the answer to it) intends to change the fundamental principle of parliamentary sovereignty nor will it have that effect.’ Professor Michael Keating, a constitutional scholar, said Bain had made it clear that she had doubts about the bill’s legality but was maintaining her political neutrality in seeking the high court’s decision. “It’s unusual to get an advisory decision from the high court, because that’s what it really is,” Keating said. “Normally you would wait until a bill is passed to refer it [to the court]. It seems to be very sensible.’ Sturgeon said last week that if the court ruled against the bill, she would use the next general election as a “de facto referendum” where the Scottish National Party would be empowered to open independence talks if it won a majority of votes in Scotland. . The Scottish Greens have since claimed that votes for their party would count towards this total. Opposition parties were furious Bain’s letter had been published during the Holyrood recess: she had been asked to appear before MSPs to answer questions about the high court application. Donald Cameron, spokesman for the Scottish Conservative Constitution, said: “Once again we can see exactly what the SNP are doing – playing political games by going to court to make a complaint.”