Pierre Poilievre, the leader of the Conservative Party, was unseated as the parliamentary representative of his Ottawa district in a stunning upset that could put his leadership of the party in question.

Mr. Poilievre was first elected in 2004 as the member of Parliament representing Carleton, a largely rural district bordering parts of the Ottawa River. His long-held Conservative seat was flipped to the Liberal Party.

Bruce Fanjoy, the Liberal candidate who is a well-known community volunteer but was initially considered a long shot, won the race.

Mr. Poilievre embraced some of Mr. Trump’s rhetoric, railing against “radical woke ideology” while pledging to defund Canada’s national broadcaster and cut foreign aid.