Aileen McHarg, Professor of Public Law and Human Rights, University of Durham.

"The court has declared that the prorogation is unlawful, but it has not made the order requiring Parliament to reconvene and is leaving questions of formal orders to the Supreme Court.

"The Government has launched and appeal to the decision which I expect the Supreme Court will hear next week. 

"I am very surprised by the decision to rule that the prorogation of Parliament is considered unlawful. 

"There's no precedent for this. It has always been thought that the exercise of prerogative powers - those that derive from the Queen - are not justiciable.

READ MORE: Court of Session rules proroguing Parliament was unlawful

"We have not seen the full judgement yet, only a summary. But given the huge constitutional stakes here it seems that the Court of Session felt compelled to make a decision.

"In his written submission Lord Carloway, says that normally prorogation would not be reviewable by the courts, but because of the circumstances the court has made its decision to uphold constitutional principles.

"All eyes will now be on the Supreme Court. The Supreme Court is the end of the road, legally."

HeraldScotland:

Joanna Cherry, MP (right), outside the Court of Session

Nick McKerrell, a lecturer in law at Glasgow Caledonian University (GCU) 

“This was a pretty unexpected judgment from the Inner House of the Court of Session and strongly overrules the findings of Lord Doherty’s ruling last week,”

“The Lord President – the top judge in Scotland – said the decision to suspend Parliament could only be reviewed if its purpose was to ‘stymie parliamentary scrutiny’.

“This was because of the length of time and the documents released showing the political discussions around prorogation that took place.

READ MORE: The Court of Session's damning statement on Boris Johnson's 'unlawful' decision​

"The other two judges supported this.  Significantly, all argued that in most normal circumstances the decision to prorogue could not be reviewed by the Courts which shows how exceptional this situation is.

“Ultimately then the court said the decision to suspend Parliament is ‘null and is of no effect’.

“However, this will now be appealed to the Supreme Court of the United Kingdom in London next Tuesday. This will now be a major showdown.”