The highest civil court in Scotland on Wednesday declared parliament’s prorogation by the Boris Johnson government amidst Brexit rows as unlawful, ruling that the move was motivated by the “improper purpose of stymying Parliament”, setting off another row in Westminster.

The controversial prorogation until October 14 took effect in the early hours of Tuesday following criticism by House of Commons speaker John Bercow, among others. The Supreme Court is due to hear a another challenge to the prorogation next Tuesday.

Labour and other opposition parties that saw the prorogation as the Johnson government’s bid to avoid scrutiny of its approach to Brexit, called the ruling ‘historic’ and demanded that parliament be recalled in view of the ruling, but Downing Street resisted it.

A UK government spokesperson 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.”

However, the ruling will not lead to the immediate reopening of parliament, despite demands from Labour, Scottish Nationalist Party and others, because it did not order the cancellation of the prorogation.

Judge Carloway said: “We are of the opinion that the advice given by the government to her majesty the Queen to prorogue parliament was unlawful and that the prorogation itself was unlawful”.

“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.”