POLITICIANS behind a cross-party legal challenge to the UK Government look set to appeal after their case was rejected by Scotland’s highest civil court yesterday.

The group was seeking a referral to 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 group, which includes Green MSP Andy Wightman, SNP MP Joanna Cherry – who is also a QC – Labour MP Chris Leslie, LibDem MP Tom Brake and Jo Maugham QC, had argued the legal uncertainty surrounding the issue has to be resolved so they can carry out their duties as democratically elected representatives.

Their attempt to have the issue referred to the Luxembourg court was knocked back by the Court of Session in Edinburgh. Lord Boyd ruled the question being asked was “hypothetical” and the conditions for a reference had not been met. On Twitter, Maugham said the group is likely to appeal.

Lord Boyd noted that the court was being asked by a number of MPs to settle a legal dispute in the middle of the legislative process. In his written ruling, Lord Boyd said: “In my opinion that is a clear and dangerous encroachment on the sovereignty of Parliament.

“It is for Parliament itself to determine what options it considers in the process of withdrawing from the European Union. It is for Parliament to determine what advice, if any, it requires in the course of the legislative process.”

He concluded: “The facts upon which the ECJ would be asked to give an answer could not at this stage be ascertained, simply because they have not occurred.”

Meanwhile, Theresa May still has full confidence in Boris Johnson after his explosive comments on Brexit, Downing Street has said.

The Foreign Secretary told a private dinner there was a risk Brexit “will not be the one we want” and would keep the UK “locked in orbit” around the EU.

Speaking at the gathering of the Conservative Way Forward, a Thatcherite campaign group, he branded the Treasury the “heart of Remain” and claimed negotiations were approaching a “moment of truth”.

Johnson called for “guts” in exit talks and warned of a Brexit “meltdown”.

Friends of Johnson said it was “disappointing” that the dinner had been covertly recorded.

Scottish First Minister Nicola Sturgeon said the Foreign Secretary had “no credibility whatsoever. These leaked comments this morning beggar belief”, she told BBC Breakfast.

“It speaks volumes that Theresa May cannot get rid of Boris Johnson or any other of her Cabinet members who are causing so much difficulty because of the weakness at the heart of her position.”