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.

Canadian Finance Minister Chrystia Freeland quit on Monday after clashing with Prime Minister Justin Trudeau on issues including how to handle possible U.S. tariffs, dealing an unexpected blow to an already unpopular government.

Canadian Prime Minister Justin Trudeau is facing the biggest test of his political career following the resignation of Finance Minister Chrystia Freeland, long one of his most powerful and loyal ministers.