Brexit: What happened at the Supreme Court?

A ruling on the legality of Boris Johnson's decision to suspend Parliament is due to be announced by the Supreme Court on Tuesday.

The government has been arguing that suspending Parliament was lawful and not a matter for the courts, whereas campaigners have claimed the PM is trying to stop MPs scrutinising Brexit policy.

The BBC's Mark Easton explains the importance of hearing, and what may happen next.

23 September 2019