On December 16th this fate befell Justin Trudeau, Canada’s prime minister, when Chrystia Freeland left his cabinet. She marked her exit by publishing a scorn-fuelled note accusing Mr Trudeau of resorting to “costly political gimmicks” in his efforts to shore up his popularity with Canadians through tax breaks and handouts.

No minister is ever truly irreplaceable. But aside from Trudeau himself, no minister has been more central to this Liberal government than Freeland. Her explosive resignation is a shattering blow to Trudeau’s government.

Chrystia Freeland, who held the finance portfolio, had been the most powerful minister in the Trudeau government for years.