Dominic Raab, one of the candidates for Conservative leader, recently made headlines when he said he would be willing to prorogue Parliament to prevent MPs from blocking a no-deal Brexit. To say this has caused a stir would be an understatement, and Raab has been criticized by politicians from across the political spectrum. But what is prorogation, and could it actually be used to ensure a no-deal Brexit?
Prorogation is a prerogative act of the Crown whereby the Sovereign terminates a parliamentary session without dissolving Parliament. There’s nothing particularly novel about it, and Parliament is typically prorogued each year before the Queen’s Speech. The ceremony for prorogation is similar to the State Opening of Parliament, though the Monarch hasn’t prorogued Parliament in person since the 19th century. Instead, the Sovereign designates several ‘Lords Commissioners’ to carry out the ceremony on their behalf. The commissioners don their parliamentary robes and bicorn hats (or tricorn hats, if they’re women) and the Commons are summoned to the bar of the Lords. There’s a lot of hat doffing, outstanding bills receive Royal Assent, and the principal commissioner (usually the Leader of the House of Lords) reads a speech from the Queen setting out the Government’s achievements over the past session. Finally, there’s an announcement that Parliament is prorogued to a certain date and everyone goes home. In other words, it’s all very British.
It’s not hard to see why prorogation would be an attractive tactic for a hardline Brexiteer Prime Minister. Unlike an early dissolution of Parliament (which requires MPs’ assent), prorogation is a matter for the Crown alone, and it could last for several weeks or even several months. And despite what John Bercow might think, if the Queen did prorogue Parliament, MPs couldn’t do anything about it. Any attempt to ignore Her Majesty’s command would be illegal and unconstitutional, and any business transacted after prorogation would be null and void.
Despite Raab’s tough talk, prorogation wouldn’t necessarily offer an easy solution to the Brexit problem. For starters, prorogation is ultimately in the gift of the Queen, and while she normally exercises this power on the advice of her ministers, Her Majesty might be reluctant to grant a prorogation if it would thwart the will of the Commons. One could argue that such a tactic would gravely undermine parliamentary democracy, in which case the Queen could conceivably decline to accept her Prime Minister’s advice. If she refused, the Prime Minister’s only recourse would be to resign, but it’s far from certain that Raab (or anyone else) would choose to fall on his sword since resignation could open the door to an alternative government that would stop Brexit outright.
Also, any attempt to use prorogation to thwart the Commons would be so controversial that the Prime Minister would likely encounter stiff opposition from their own benches. Given the Tories’ lack of an overall majority, it wouldn’t take many defections to bring down the government in a vote of confidence (indeed, Dominic Grieve has said he would be willing to vote against the Government on a confidence motion to stop a no-deal Brexit). Consequently, they might be kicked out of Downing Street before the Queen had a chance to weigh in on the matter.
While talk of prorogation is likely just an attempt to court the Brexiteer vote, it does illustrate how the Britain’s uncodified constitution relies on fair play instead of legally enforceable rules. It also highlights the tension between the Sovereign’s dual roles as ceremonial head of state and constitutional umpire. It would be a shame if Brexiteers, in their zeal to leave the EU, ended up damaging the very constitution that they claim to cherish so much.
 The last time prorogation was controversial in the United Kingdom was when John Major was accused of proroguing Parliament early ahead of the 1997 General Election in order to avoid the fallout from a report into the cash-for-questions scandal. In Canada, however, the practice gained considerable notoriety after the Harper Government used it to avoid a vote of no confidence in 2008-09.
 Annual prorogations allow multiple Queen’s Speeches over the course of a Parliament since the Queen only addresses peers and MPs at the start of a session.
 Nowadays, these commissioners are usually the Lord Speaker, the Leader of the House of Lords, the Leader of the Opposition, the Leader of the Liberal Democrats, and the Convenor of the Crossbench Peers, though the Archbishop of Canterbury and the Lord Chancellor are also designated pro forma. In years past, the list of potential Lords Commissioners was far lengthier (see this example from 1832!).
 While the eminent constitutional expert Vernon Bogdanor has suggested that the Queen should still follow the convention of acting on ministerial advice in these circumstances, the dangers of a no-deal Brexit and the damage to parliamentary democracy might spur the Palace to take a different approach.