INDEPENDENCE supporting MSPs must change Holyrood’s rules and call an early election to be used as a de facto vote, an SNP MP has urged.

Angus MacNeil, who represents Na h-Eileanan an Iar in Westminster, said forcing an early Scottish Parliament election was “risk-free” – even if the UK Government tried to stop it from going ahead.

But Aileen McHarg, professor of public law at Durham University, said the tactic could be legally risky and potentially open to a challenge from the UK Government that the Edinburgh administration was treading on reserved matters.

While calling an extraordinary Scottish Parliament election currently requires a two-thirds majority vote, McHarg said the part of the Scotland Act which sets that rule could be changed by MSPs with only a simple majority.

This would mean the SNP could easily change the rules to pave the way for an early vote in a similar fashion to the Tories in 2019 passing a one-line bill to get around the Fixed-term Parliaments Act, McHarg said.

“If it were clear that the only reason for doing that one-off change was to have a one-off early election rather than a general change to the rules, if the purpose of that were to call a de facto referendum then you certainly would be vulnerable to an argument that [it] encroached upon the reserved matter of the Union,” she added.

The Supreme Court’s judgment last year in the indyref2 case put beyond doubt that the Scottish Parliament could not legislate on reserved matters like the constitution without the permission of Westminster.

McHarg added: “You’d be vulnerable to exactly the same arguments that were successful against the [Scottish Government’s] referendum bill. You’d look not to the legal effect but to the political effects and the political purpose. So that would be a vulnerable route.”

But MacNeil, who has long expressed frustration with the cautious approach demonstrated by his party’s high command, said there were no downsides to the early Holyrood election strategy, claiming that a UK Government challenge to a poll would boost the case for independence.

He said a move in that direction would be seen by voters as “authoritarian” and that a UK Government challenge, were the SNP to run on a single-issue manifesto, would be a “fantastic” result for the Yes cause.

MacNeil added: “On the basis of a manifesto appearing, a manifesto at an election, they [UK ministers] would then say the election’s not legal or valid – that’s a fantastic situation to get ourselves into.

“That’s exactly what you want the Unionists doing – highhandedly saying ‘If you have an election and you have a manifesto, and we don’t like what you have in the manifesto, we’ll declare it null and void or illegal’ – I think you’re on a lot safer ground there.

“The power is there to dissolve parliament, MSPs choose to dissolve it, after it’s dissolved political parties then decide what the manifesto is, after seeing the manifesto the UK Government goes, ‘No you can’t have that election’?

“Happy days, nothing like a bit of oppression for independence.”

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He added: “It’s risk-free for us – because what happens [if a legal challenge succeeds]? You reinstate the parliament, the one elected in 2021. You can’t go around saying to people you can’t have an election because we suspect this is what you want to do. This is really the behaviour of the mad dictator, this kind of carry-on.”

The option of calling an early Holyrood election is not on the SNP’s official slate of preferred policies to execute the de facto referendum plan.

SNP members will meet at a special conference in March to hash out its approach on the de facto referendum strategy. The party’s national executive committee has slated two official options, approved by SNP HQ, which are either fighting the next UK General Election as a de facto referendum and claiming victory if pro-Yes parties win a majority of votes, or fighting the next election on the basis they will again request the UK Government to allow a second referendum.

The UK Government has repeatedly denied the Scottish Government’s requests to hold indyref2.