Prime Minister Justin Trudeau’s hold on power was threatened on Monday after the deputy prime minister who led Canada’s response to the first Trump administration resigned abruptly, in a stinging rebuke to the country’s leader.

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.

Chrystia Freeland resigned her post as finance minister today, sending shockwaves across Ottawa and the Canadian political world. Freeland posted a letter addressed to Prime Minister Justin Trudeau on social media. See my letter to the Prime Minister below // Veuillez trouver ma lettre au Premier ministre ci-dessous pic.twitter.com/NMMMcXUh7A