A judge in Scotland's highest civil court has said it would be "unprecedented" for an official to sign a letter asking the EU for a Brexit delay

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.

Legal action began on Friday asking the court to force Boris Johnson to seek an extension to avoid leaving the EU without a deal.

The so-called Benn Act was passed by parliament last month requiring the UK 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 are suspicious 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".

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 for Tuesday.