SUGGESTIONS that Scottish Government spending on building the case for independence would be illegal in the wake of the Supreme Court’s indyref2 ruling have been dismissed by a constitutional expert.

After judges found that Holyrood requires Westminster’s permission to hold a fresh vote on leaving the Union – because doing so would interfere with reserved powers – opposition politicians took aim at ministers’ ongoing work on independence.

Tories roughly estimated that the Government is set to spend more than £1.5 million a year working on the independence prospectus, after finding that 25 officials are involved in the work. They calculated the figure by adding up the maximum salaries of civil servants in relevant pay bands.

READ MORE: Indyref2 ruling ‘very problematic’, constitution expert says

There is also £20m set aside for holding indyref2 next year, but deputy first minister John Swinney is set to address how that cash will now be used at next month’s budget.

Donald Cameron (below), the Tories’ shadow constitution secretary, called for the “Scottish Government’s independence unit [to] be disbanded” and for civil servants involved to be moved to other departments.

The National:

Speaking to The Sunday Times, he added that using the next General Election as a de facto referendum is a “party-political tactic” and not a government matter.

“Therefore, it would be utterly scandalous if independent, publicly funded civil servants continued to be used for what is now purely SNP campaigning,” the MSP said.

Scottish LibDem leader Alex Cole-Hamilton also argued that having civil servants working on the independence case following the court’s verdict could be outside of Holyrood’s powers and “incompatible with the civil service code”.

However Aileen McHarg (below), a professor of public law and human rights at Durham University, dismissed any claim of illegality.

The National: Aileen McHarg, Professor of Public Law at the University of Strathclyde.

“On Thursday morning the usual suspects tried to push this line in a debate on an urgent question on the indyref ruling in the House of Lords,” she recalled.

“The fact that the Scotland Office minister, Lord Offord, studiously ignored it tells you all you need to know about its legal accuracy.”

The professor went on: “It only requires a moment's thought to know that it's a ludicrous position to adopt.

“Holyrood legislation is (theoretically) at risk of challenge indefinitely. In Salvesen v Riddell a provision was struck down 10 years after enactment. Should all the money spent on enacting it have retrospectively been declared unlawful?

“How would you separate out the sum involved from the rest of the statute in question? Would any expenditure on unsuccessfully defending the legislation on court also have been caught?”

READ MORE: John Curtice: Using election as de facto indyref2 is 'legitimate'

The expert added that this position would also suggest that civil servants working on new devolved powers are breaking the law until the change comes into force.

She concluded that it’s a “cheap line” pushed by “deeply unserious politicians”.

The Scottish Government has insisted that it will continue working on “what could be done with the full powers of independence, reflecting clear programme for government commitments”.

Speaking to the BBC on Sunday morning, SNP deputy leader Keith Brown defended plans to push ahead with the de facto referendum proposals.

He argued the UK Government is “scared” of allowing a referendum on Scottish independence because it knows it will lose.

“I think they know they’re going to lose this, that’s why they are doing everything they can to twist democracy, to refuse the opportunity for the people of Scotland, because they know they’re going to lose,” he told the Sunday Show.

Brown pointed to a snap poll by Find Out Now for Channel 4 of 1006 Scots, which suggested 51% would vote for the SNP if they knew their vote would be used to negotiate independence.