The Queen’s prorogation of parliament on Wednesday, at British Prime Minister Boris Johnson’s request, is at once constitutional and a striking challenge to constitutional norms. But Johnson believes it is necessary if Brexit is to be automatically effected on Oct. 31st.

Still, the stakes are high. Prorogation, which suspends parliament from sitting in a period it might otherwise be expected to sit, is an accepted right of a sitting government. But it has never been applied in a manner such as this: as a means of denying parliamentary action opposed by the government. Johnson denies that this is his intent, but few believe him.