He rejected an application from lawyers acting for 75 anti-Brexit MPs and peers for an emergency interdict, or injunction, requiring Johnson to suspend the prorogation.

In a surprise development, Aidan O’Neill QC, the lawyer acting for the MPs and peers, called in court for Johnson to provide a sworn affidavit under oath setting out why he needed to prorogue parliament.

O’Neill also said he reserved the right to call Johnson to give evidence in court at a later date.

Joanna Cherry QC, the Scottish National party MP who is leading the legal challenge, urged the prime minister to provide a statement. “Tell the court the truth in sworn testimony,” Cherry said outside court. “[If] he believes that he has a good case for prorogation, he should have the guts to swear an affidavit.”

She said an off-guard disclosure by Ben Wallace, the defence secretary, caught on microphone on Thursday, that prorogation was a political gambit to frustrate anti-Brexit MPs in parliament was powerful evidence in their favour.

Doherty said he saw no urgent need for a temporary interdict ordering Johnson to drop prorogation at this stage but he agreed that the full case needed to be heard urgently.