Canada’s deputy prime minister and minister of finance, Chrystia Freeland, has resigned from her positions amid growing tensions with Prime Minister Justin Trudeau over the impending threat posed by U.S. President-elect Donald Trump’s tariffs.

Ms Freeland’s resignation came on Monday barely a few hours to her release of the country’s first economic plan ahead of Mr Trump’s inauguration in January.

Ms Freeland’s shocking decision ultimately leaves Mr Trudeau without a key political ally, raising significant doubts about his political survival, following Mr Trump’s pledge to slam a 25% levy on all Canadian goods and services, a threat that has strained the relations between Canada and the U.S.

In the resignation letter addressed to the prime minister, Ms Freeland stressed the need for Canada to keep its “fiscal powder dry today” so that they have the reserves for a “coming tariff war”.

“For the past number of weeks, you and I have found ourselves at odds about the best path forward for Canada”, Ms Freeland wrote.

“Our country today faces a grave challenge. The incoming administration in the United States is pursuing a policy of aggressive economic nationalism, including a threat of 25% tariffs. We need to take that threat extremely seriously”, she added.

Ms Freeland further warned Mr Trudeau against “costly political gimmicks”, saying they can make Canadians doubt whether the government understands the “gravity of the moment”.

“That means pushing back against ‘America First’ economic nationalism with a determined effort to fight for capital and investment and the jobs they bring. That means working in good faith and humility with the Premiers of the provinces and territories of our great and diverse country, and building a true Team Canada response”.

Last month, Mr Trudeau said that he promised Mr Trump that Canada would shore up border security in surveillance, after both of them were pictured in a thrilling dinner in Florida.

Ms Freeland was scheduled to announce the government’s delayed fall economic statement on Monday, anticipated to include details of increased enforcement at the U.S.-Canada border. She had also noted that the plan would outline policies to deepen development and investment in Canada.

It is now unclear when the said statement will be delivered and who will deliver it.

Ms Freeland’s resignation is on the heels of her alleged disagreement with Mr Trudeau over proposals for temporary tax breaks and other spending measures.

The letter is also coming amid lingering uncertainty in Canada over the potential impact of U.S. tariffs which Mr Trump said would be slammed on Canada, Mexico and China, unless they take action against drug and human smuggling.