The UK Supreme Court on Tuesday heard two simultaneous appeals over whether Prime Minister Boris Johnson broke the law by suspending Parliament for five weeks in the run-up to the Brexit deadline, currently scheduled for October 31.

Lord Pannick QC represented anti-Brexit campaigner Gina Miller, appealing from an English High Court ruling that Johnson’s decision to prorogue Parliament was a political decision and therefore out of the purview of the judiciary. Pannick argued that Johnson had suspended Parliament for the improper purpose of “silencing” MPs in advance of Brexit. Johnson maintains that the prorogation had nothing to do with the impending exit date.

Edinburgh’s Court of Session, Scotland’s highest civil court, ruled last week that the suspension was unlawful and that Johnson had misled the Queen as to its purpose. The government appealed from this ruling, claiming that the Court of Session had “nakedly entered the political arena” by attempting to strike down what they say is a legitimate political decision by the PM.

The Supreme Court will rule on whether the validity of the prorogation can be properly decided by the judiciary, and if so, whether Johnson indeed broke the law. Supreme Court President Lady Hale stressed that the court would not decide any larger political issues concerning Brexit by ruling on the two appeals, and that the deadline of October 31 would not be affected.