OTTAWA—Canada’s Finance Minister Chrystia Freeland quit the Liberal government cabinet Monday, a surprise departure that casts further doubts about how long Prime Minister Justin Trudeau can hold on to his job given the government’s deep unpopularity.

The stunning move raised questions about how much longer the prime minister of nearly 10 years — whose popularity has plummeted due to concerns about inflation and immigration — can stay on.

Chrystia Freeland said the decision came from a disagreement with Justin Trudeau over how to respond to US President-elect Donald Trump's tariff threats.