A legal bid arguing Boris Johnson's Brexit deal is unlawful and attempting to stop it being voted on by MPs has been rejected by a judge at a Scottish court.
Campaigner Jo Maugham QC was behind the petition which was heard at the Court of Session in Edinburgh - Scotland's highest civil court.
It was suggested that the proposed deal breaches UK law by leaving Northern Ireland in a separate customs arrangement to the rest of the country, contravening tax legislation.
Changes to the agreements around Northern Ireland were a key part of the deal agreed between the Government and the EU on Thursday.
Government lawyers defended the agreement and called the legal action a "direct and manifest interference with Parliament".
On Friday evening, Lord Pentland rejected the campaigners' argument. The judge said: "The orders sought would unquestionably interfere to a major extent to the proposed proceedings in Parliament.
"I cannot see that it would be right for Parliament to be invited to consider a draft treaty which the court had suspended on the basis that it was unlawful.
"It is a cardinal principle of constitutional law that the courts should not intrude on the legitimate affairs and processes of Parliament."
Mr Maugham, who lodged the petition on Thursday, tweeted after the ruling: "That was a difficult decision to make. It is difficult to move quickly and accurately and, the court has found, I got that decision wrong.
"We will review the decision carefully but my instinct is that we are unlikely to proceed to a full hearing for reasons indicated above."
Aidan O'Neill QC, acting for the petitioners, had told the court that Mr Johnson's Brexit deal would mean a "continuing regime of EU law applicable to Northern Ireland" - contrary to Section 55 of the Taxation (Cross-Border Trade) Act 2018.
He said this would breach the Act's terms by creating different customs rules in Northern Ireland to the rest of the UK, leaving the deal void and unsuitable to be put before Parliament.
Mr O'Neill said: "The agreement which was presented yesterday is void; is of no effect as a matter of law."
In his judgment, Lord Pentland said the argument that the new Brexit deal was incompatible with the Trade Act was "at best a weak one".
He said the "clear intention" underlying the proposed deal was Northern Ireland will remain part of the UK's customs territory.
He added: "There is nothing to show that this will not play out as intended and work in a satisfactory manner."
Additional reporting by PA Media
