Jeremy Corbyn is set to make his keynote speech to the Labour Party conference.
The speech will be a day earlier than scheduled after the Supreme Court declared the five-week prorogation of Parliament unlawful.
Speaker John Bercow said the Commons will resume on Wednesday morning in light of the judgment, with Mr Corbyn - who called for Prime Minister Boris Johnson to "consider his position" - set to take to the stage in Brighton at 4.30pm.
Mr Johnson said he "strongly disagrees" with the ruling but will respect the decision and return from the US to attend Parliament.
Follow live updates from our team in Brighton HERE.