Both the Scottish and Welsh Governments will be allowed to intervene in a court battle over how the Brexit process should be formally triggered, the Supreme Court has announced.
The government is appealing against the High Court ruling that MPs must be allowed to vote on triggering Article 50. The hearing is due to be heard next month.
Counsel for the Scottish Government is being invited by the Supreme Court justices to address the court on the relevance of points of Scots law so far as they do not form part of the law of England and Wales, the Press Association reports.
The Independent Workers Union of Great Britain, which describes itself as “fighting for the rights and welfare of some of the most vulnerable and under-represented workers in the UK”, has also been given permission to make submissions to the court.
The Attorney General for Northern Ireland has made a reference to the court on devolution issues and did not need permission to intervene.
Earlier this month the High Court ruled that Prime Minister Theresa May does not have the authority to trigger Article 50 without the agreement of Parliament.
The historic legal challenge over Brexit was brought by investment fund manager and philanthropist Gina Miller and Deir Dos Santos, a hairdresser, with other “concerned citizens”.
Three senior High Court judges ruled that the Prime Minister does not have power to use the royal prerogative to trigger Article 50 of the Lisbon Treaty to start the two-year process of negotiating Brexit without the prior authority of Parliament.
The decision means MPs will be given a vote on leaving the EU.
May had argued she had the authority to use the royal prerogative to trigger Article 50 without a vote.
She has previously said that MPs who wanted to be given a say were trying to “subvert democracy”.
Government lawyers said prerogative powers are a legitimate way to give effect “to the will of the people” who voted by a clear majority to opt for Brexit in the June EU referendum.
However the High Court disagreed and said May unlawfully intended to by-pass parliamentary scrutiny while taking irreversible steps to remove statutory rights granted to UK citizens under the European Communities Act 1972, which made EU law part of UK law.
May and her ministers are now asking the Supreme Court to overturn that unanimous decision.
Their appeal is due to be heard by 11 judges between December 5 and 8, with a judgment expected in the new year.