Brexit: Judge says legal bid to stop Boris Johnson forcing no-deal will be heard before 31 October, in win for campaigners

Full hearing of case will go ahead on 6 September

A legal challenge seeking to prevent Boris Johnson from suspending parliament to force through a no-deal Brexit will be heard before the 31 October deadline, in a boost for pro-EU campaigners.

The bid – backed by more than 70 MPs and peers – is urging the Court of Session in Edinburgh to rule that it would be “unlawful and unconstitutional” for the prime minister to prorogue parliament so that the UK can leave the EU without a deal.

With just 79 days until the Halloween deadline, the initial session on Tuesday decided to hold a full hearing of the case on 6 September. A judgment is expected in advance of the Brexit deadline.

Mr Johnson has repeatedly pledged to deliver Brexit by the Halloween deadline come what may, and has not ruled out attempting to suspend parliament to bypass MPs.

A cross-party group of MPs is backing the legal petition – supported by the Good Law Project, which won a victory at the European Court of Justice over whether the UK could unilaterally cancel Brexit by revoking Article 50.

Ahead of the hearing Jolyon Maugham QC, the director of the Good Law Project, said: “A man with no mandate seeks to cancel parliament for fear it will stop him inflicting on an unwilling public an outcome they did not vote for and do not want.

“That’s certainly not democracy and I expect our courts to say it’s not the law.”

The legal papers state: “Seeking to use the power to prorogue parliament to avoid further parliamentary participation in the withdrawal of the UK from the EU is both unlawful and unconstitutional.”

Warning that “the exercise of the power of prorogation would have irreversible legal, constitutional and practical implications for the United Kingdom”, the challenge calls for the court to declare that proroguing parliament before 31 October would be both unconstitutional and unlawful by denying MPs and lords the chance to debate and approve the decision.

The Scottish Labour MP Ian Murray, who is backing the legal challenge, added: “When Boris Johnson unveiled his vacuous slogan ‘taking back control’, voters weren’t told this could mean shutting down parliament.

“The prime minister’s undemocratic proposal to hold Westminster in contempt simply can’t go unchallenged.”

“On behalf of voters across the UK, this cross-party legal challenge aims to prevent him riding roughshod over British democracy.”