Boris Johnson's suspension of Parliament has been ruled unlawful by Scotland's highest civil court.

The Court of Session originally backed the government's position, but overturned its decision on appeal.

The case, brought by a cross-party group of around 75 politicians, will now go to the UK Supreme Court.

Among the petitioners are SNP MP Joanna Cherry and Liberal Democrat leader Jo Swinson, backed by barrister Jolyon Maugham QC of the Good Law Project.

First Minister Nicola Sturgeon has called on Parliament to be "recalled immediately" after it was officially suspended in the early hours of Tuesday.

Responding to the judgement, Cherry tweeted: "All 3 judges in Scotland's highest court of appeal rule #Prorogation #unlawful! #Cherrycase succeeds.

"Huge thanks to all our supporters & our fantastic legal team who have achieved the historic ruling that #prorogation is #unlawful #Cherrycase #Brexit."

Swinson said: "Scottish judges have found in favour of 75 MPs (including me and other Liberal Democrats.)

"We argued that Boris Johnson's Parliament shutdown is illegal, and designed to stifle parliamentary debate and action on Brexit."

Judge Lord Doherty originally dismissed a challenge against the suspension last week, which went ahead in the early hours of Tuesday amid chaotic scenes in the Commons.

Lord Doherty said shutting down Parliament - also known as prorogation - was for politicians and not the courts to decide.

But three judges of the inner house, the supreme civil court in Scotland, disagreed with Lord Doherty's ruling.

Mr Maughan QC confirmed the Supreme Court in London would hear the case next week.

He tweeted: "We have won. Appeal begins in the Supreme Court on Tuesday.

"We believe that the effect of the decision is that Parliament is no longer prorogued.

"I have never been able to contemplate the possibility that the law could be that our sovereign Parliament might be treated as an inconvenience by the Prime Minister.

"I am pleased that Scotland's highest court agrees. But ultimately, as has always been the case, it's the final arbiter's decision that matters."

A summary of the court opinion, published by the Scottish Courts and Tribunals Service, states: "The inner house of the Court of Session has ruled that the Prime Minister's advice to HM the Queen that the United Kingdom Parliament should be prorogued from a day between 9 and 12 September until 14 October was unlawful because it had the purpose of stymying Parliament."

It continues: "All three first division judges have decided that the PM's advice to the HM the Queen is justiciable, that it was motivated by the improper purpose of stymying Parliament and that it, and what has followed from it, is unlawful."

It went on: "The court will accordingly make an order declaring that the Prime Minister's advice to HM the Queen and the prorogation which followed thereon was unlawful and is thus null and of no effect."

A UK Government spokesman said: "We are disappointed by today's decision, and will appeal to the UK Supreme Court.

"The UK Government needs to bring forward a strong domestic legislative agenda. Proroguing Parliament is the legal and necessary way of delivering this."

Nicola Sturgeon said: "Today's Court of Session judgment is of huge constitutional significance - but the immediate political implications are clear.

"Court says prorogation was unlawful and null and void - so Parliament must be recalled immediately to allow the essential work of scrutiny to continue."

Speaking at the TUC Congress in Brighton, Labour's shadow Brexit secretary Keir Starmer said: "I need to get back to Parliament, to see if we can reopen the doors and hold Johnson to account.

"The Prime Minister was not telling the truth about why he was doing it.

"The idea of shutting down Parliament offended everyone across the country, and then they felt they were not being told the truth."