Justin Trudeau said Monday that he will resign as the leader of Canada’s ruling Liberal Party, in an announcement that will fire the starting gun on a contest to replace him as prime minister.

“I intend to resign as party leader, as prime minister, after the party selects its next leader through a robust, nationwide competitive process,” Trudeau told reporters in Ottawa. “Last night, I asked the president of the Liberal Party to begin that process.”

The departure of the beleaguered prime minister follows growing calls for his resignation from inside his own party, with the Liberals lagging behind the opposition Conservative Party in opinion polls and internal battles raging over his handling of President-elect Donald Trump.

That pressure culminated with the resignation of Deputy Prime Minister Chrystia Freeland last month. Freeland, who was also the finance minister, quit unexpectedly citing concerns over the Trudeau administration’s relatively cooperative approach to the incoming Trump administration’s plan to increase import tariffs on Canadian goods by 25%.

“For the past number of weeks, you and I have found ourselves at odds about the best path forward for Canada,” Freeland said in her resignation letter, adding that the country can “ill afford” Trump’s tariff threats.

She added that leaving the Cabinet was the only “honest and viable path.”

Trudeau, who swept to power in late 2015 and has governed for nine years, has largely remained out of the public eye since then.

During his remarks, Trudeau said he was elected to fight for the middle class, which is what his administration has done.

“Over the past years, we reduced their taxes, we increased the benefits to families, we made sure the economy was focused on working for everyone, and not just a few,” he said.

In November, Trump said that he would sign an executive order imposing tariffs on all products coming to the United States from Mexico and Canada if re-elected.

“On January 20th, as one of my many first Executive Orders, I will sign all necessary documents to charge Mexico and Canada a 25% Tariff on ALL products coming into the United States, and its ridiculous Open Borders,” he said in a post on Truth Social in late November.

Days later, Trudeau visited the president-elect at his Mar-a-Lago estate in Florida, later writing in a post on X: “Thanks for dinner last night, President Trump. I look forward to the work we can do together, again.”

Trump has since taken jabs at Trudeau and Canada, suggesting making the country America’s 51st state and referring to the prime minister as the “governor” of the “Great State of Canada.”

Still, Trudeau’s popularity was waning even before his recent handling of the prospect of fresh American tariffs. Many working-class and young Canadians blame the prime minister for the country’s high rate of inflation and long-running political chaos.

The Liberals hold 153 out of 338 seats in the House of Commons. Elections will be held by late October.

The party’s popularity has declined rapidly against the opposition over the past year. The latest survey released Friday by the Canadian research firm Angus Reid found that voter support for the Liberals had sunk to an all-time low of 16%.