A CROSS-party legal challenge to the UK Government on Brexit is not “hypothetical or academic”, Scotland’s highest civil court has been told.

At a hearing at the Court of Session, lawyers acting for a group of nine politicians contested claims that the action was “premature” and “incompetent”.

The group is seeking a ruling from the European Court of Justice (ECJ) on whether the withdrawal process triggered under Article 50 can be revoked by the UK on its own without the consent of the other 27 EU member states.

The nine argue that the legal uncertainty surrounding the issue has to be resolved so they can carry out their duties as democratically-elected representatives.

The group includes Green MSPs Andy Wightman and Ross Greer, SNP MEP Alyn Smith, Labour MEPs David Martin and Catherine Stihler, SNP MP Joanna Cherry and Jo Maugham QC and has recently been joined by two English MPs.

Their attempt to have the issue referred to the Luxembourg court has already been knocked back by a Scottish judge on the basis the issue was “hypothetical and academic”, but that decision was overturned by Lord Carloway, the Lord President, earlier this year.

At a full hearing yesterday, Aidan O’Neill QC, acting for the petitioners, said the issue was “certainly not premature because it would come too late if left longer”.

He said: “This is not some ivory tower, theoretical question. We are not here to waste the court’s time or raise hypothetical issues. It’s a real dispute, a real reason this matter requires to be resolved.”

David Johnston QC, for the UK Government, argued there has been no suggestion Article 50 would be revoked, adding: “It’s not for the court to enter into a hypothetical or premature debate.”

Judge Lord Boyd said he understood the “need for speed” and would issue his decision “in very short order”.