Three judges of the Scottish Court of Session ruled on Wednesday morning that Boris Johnson’s decision to suspend the UK Parliament was illegal.

The government will appeal the ruling of Scotland’s highest court to the UK’s Supreme Court next Tuesday.

Former Conservative attorney general Dominic Grieve said Boris Johnson should resign if it the UK Supreme Court confirms the ruling that he “misled the queen about the reasons for suspending Parliament.” Queen Elizabeth II had agreed to suspend (“prorogue”) Parliament until October 14, while the UK is to leave the EU on October 31. The Queen is obliged by custom to follow the advice of the PM.

“This was an egregious case of a clear failure to comply with generally accepted standards of behaviour of public authorities,” concluded one judge Philip Brodie.

The Scottish court ruled that closing the parliament was “unlawful because it had the purpose of stymying Parliament” and contradicts two other English court judgments.

The case was brought by 75 MPs led by Joanna Cherry of the Scottish National Party.

“We feel utterly vindicated and I would be confident that the UK Supreme Court will uphold this decision,” Cherry said.

Scotland’s first minister, Nicola Sturgeon, called for Parliament to be “recalled immediately to allow the essential work of scrutiny to continue.”

Parliament last week passed a law requiring Johnson to seek an extension to the Oct. 31 deadline for Britain’s exit, essentially taking no-deal off the table. Johnson has vowed to defy the law, while his foreign secretary Dominic Raab promises the government will “challenge the law to its limit.”