A judge at Scotland’s highest civil court has said it would be “unprecedented” for an official to exercise powers to sign an Article 50 extension on behalf of Boris Johnson.
The Court of Session’s Inner House heard the unique power of nobile officium – which would allow a court official to sign the letter – has never been used over a Prime Minister.
Lord Drummond Young said: “In the circumstances of this case, it is unprecedented. There’s a question of competence.”
The three judges – Lord Drummond Young, Lord Menzies and Lord Turnbull – set the date for the hearing on this aspect of the case for Tuesday.
Meanwhile, a hearing has now begun in the Outer House of the Court of Session on whether the Prime Minister can be forced to extend Article 50.
The legal action – led by businessman Vince Dale, SNP MP Joanna Cherry QC and Jolyon Maugham QC – will ask the court to require Mr Johnson to seek an extension to avoid leaving the EU without a deal.
The so-called Benn Act was passed by Westminster last month requiring the Government to ask for an extension until January 31 if an agreement is not reached with the EU by October 19.
Opponents to no-deal say they fear the Prime Minister will try to thwart the legislation in order to fulfil his vow to leave the EU on October 31 “do or die”.
The trio behind the court action are seeking an order to ensure Mr Johnson requests an extension to the Article 50 process if he refuses to abide by the terms of the Benn Act.
In an earlier statement, Ms Cherry said: “Like much of what Boris Johnson says, there is a gulf of truth between the obvious facts of the matter and what he and his Government have been saying.
“He cannot be trusted, and this court action is about ensuring he abides by the law.
“If Boris Johnson tries to defy the law and defy both the Holyrood and Westminster parliaments by crashing out of the EU without a deal – then we are calling on the Scottish courts to uphold the law.”
Speaking to BBC Radio Scotland’s Good Morning Scotland programme on Friday, she added: “We’re not bringing this case because we think there’s any loophole in the Benn Act.
“We’re bringing this case because we’re dealing with a British Prime Minister who brags about not obeying the law and has form for doing things that are unlawful.
“Boris Johnson is not above the law, whether in Scotland or south of the border, thanks to the decision of the UK Supreme Court.”
The SNP MP also said she hopes the Prime Minister will be clear on his position about obeying the Benn Act.
She said: “If this court case achieves nothing else but getting him to be clear about what his position is, then it will have achieved something.”
Ms Cherry previously won a Supreme Court case against the Government which found the planned prorogation of Parliament until October 14 was unlawful.