After weeks of speculation, Boris Johnson has confirmed that Parliament will be prorogued shortly after MPs return from their summer recess. This is very grave news. It dramatically heightens the chances of a no-deal Brexit, and it also raises the prospect of a constitutional crisis.
Johnson and his allies have been trying to portray prorogation as business as usual, noting that a Speech from the Throne is long overdue. They’re right, up to a point. Her Majesty traditionally addresses Parliament every year, yet there hasn’t been a Queen’s Speech since June 2017. However, while prorogation usually lasts for a few days to a week, this prorogation will last approximately a month, leaving MPs with very little time to stop a no-deal Brexit.
Some may criticize the Queen for accepting Johnson’s advice, but she didn’t really have much room for maneuver. Johnson is her Prime Minister, and one of the cardinal rules of Britain’s constitutional monarchy is that the Sovereign acts on ministerial advice. As today’s events have shown, that convention can lead to problematic outcomes, but from a constitutional standpoint, accepting Johnson’s advice was probably the least-bad option. MPs still have a (very narrow) window in which to block a no-deal Brexit, so politicians can still take matters into their own hands. If they can’t (or won’t) act, the blame lies with them, not Her Majesty. The Crown is not obliged to save politicians from their own fissiparousness.
At this point, MPs essentially have two options: they can try to pass legislation to block a no-deal Brexit, or they can try to kick Johnson out of Downing Street through a vote of no confidence. Both options seem like longshots. Legislation can only happen if a) opponents of no-deal seize control of the Order Paper and b) get the necessary legislation through the Commons and the Lords in a matter of days. A successful vote of no-confidence, on the other hand, would require MPs to rally behind an alternative Prime Minister within the fourteen-day period prescribed by the Fixed-term Parliaments Act 2011. As Leader of the Opposition, Jeremy Corbyn has the best claim to lead an alternative government, but he’s accompanied by so much baggage that it’s not clear that he could actually command the confidence of the Commons. Also, it’s not clear how the fourteen-day period set out by the Act can be reconciled with the fact that Parliament is to be prorogued at some point between September 9 and September 12. That is uncharted territory.
There is also a possibility that the courts could become involved, but this seems unlikely. Prorogation is a prerogative act of the Crown, and the Sovereign’s acts are not subject to judicial review. Some have suggested that the courts might be willing to review Johnson’s advice to the Queen, but I’m skeptical that such a challenge would succeed. Johnson’s decision may well be a bad one, but that doesn’t make it illegal. If prorogation violated an Act of Parliament, that would be a different story. But while opponents of a no-deal Brexit had hoped that section 3 of the Northern Ireland (Executive Formation, etc) Act 2019 might prevent prorogation, the actual terms of Johnson’s prorogation would appear to comply with the Act’s provisions. Consequently, it doesn’t appear that this prorogation violates statute law, which makes a legal challenge far less sustainable.
This incident illustrates one of the problems inherent in
the British constitution. As Philippe Legassé observed on
Twitter, “[t]oday is a good example of the difference between
constitutional convention (the Queen acting on advice) and constitutional norms
(political actors should exercise powers fairly and honourably).” If a Prime
Minister is intent on using the royal prerogative in a capricious manner, there
isn’t much that can be done to stop them. This may well lead to calls for a codified
constitution, or even a Scandinavian-style monarchy where the Sovereign is
stripped of even notional discretion in political matters.
 It will be interesting to see the correspondence between the Palace and Downing Street on this issue once it is finally released, many years from now.
 The Act obliges the Government to publish reports on their efforts to re-establish devolution in Northern Ireland, and it requires Parliament to debate these reports within five days of their being tabled. However, after an initial report on September 4, the Government isn’t obliged to submit another report until October 9. This means the parliamentary debate wouldn’t need to take place until October 14, which is, of course, the day on which Parliament will return after being prorogued.