Back in August, I wrote a post about the circumstances in which the Queen might dismiss Boris Johnson as Prime Minister. I noted that, if Johnson were to refuse to resign after losing a vote of no confidence, Her Majesty might be obliged to sack him (though she would need to be able to find a new Prime Minister who could command the confidence of the Commons before she acted). At the time, I thought this was a rather unlikely scenario—I assumed that the ‘men in grey suits’ would convince Johnson to step down rather than put the Queen in an awkward position. But now it seems that Johnson may be impervious to their counsels. Reports in the British media suggest that Johnson would actually refuse to step down even if he lost the confidence of the Commons. Moreover, he seems to think that Her Majesty could still keep him in office in this situation.
According to an anonymous Downing Street ‘insider,’ the Queen shouldn’t dismiss Johnson even if he lost the confidence of the Commons because his dismissal would cause chaos and the economy would suffer. They note that the Lascelles principles stated that the Sovereign wasn’t obliged to grant the Prime Minister a dissolution if it would damage the economy.
The Lascelles principles are named for Sir Alan Lascelles, Private Secretary to George VI, who wrote a pseudonymous letter to the Times in 1950 which set out the scenarios in which the Sovereign might refuse a Prime Minister’s request for a dissolution of Parliament. While it’s true that Sir Alan cited economic damage as a reason for refusing a dissolution, this has little relevance to the present situation. The Lascelles principles were only concerned with the dissolution of Parliament; they have nothing to do with the dismissal of a Prime Minister. (And since the Fixed-term Parliaments Act 2011 abolished the Crown’s prerogative power of dissolution, the Lascelles principles aren’t even relevant there!)
Johnson might argue that the Lascelles principles still serve as a useful rule of thumb (i.e., if the Queen could refuse a dissolution due to the threat of economic damage, she should also refuse to dismiss a Prime Minister if their dismissal would cause similar problems). But that line of thought immediately becomes problematic. One of the core tenets of the British constitution is that the Prime Minister’s tenure ultimately depends on their ability to maintain the confidence of the House of Commons. The Sovereign cannot second-guess MPs’ decision to withdraw that confidence by allowing the Prime Minister to squat in Downing Street. If that were to happen, the United Kingdom would no longer have responsible government, and that would be a very grave turn of events indeed.
One has to hope that these reports are just bluster, but if Johnson
refuses to resign after losing the confidence of MPs and there is a viable
alternative who can take over Her Majesty’s Government, the Queen would be well
within her rights to give him the boot.
 This line of thought seems ironic, given how dangerous a no-deal Brexit could be to the economy.
 Dissolutions were a bit of an exception to the normal rule that the Monarch must act on the Prime Minister’s advice. As Sir Alan noted in his letter, the Prime Minister could only ask for a dissolution; they could not issue formal advice on the matter.