Pierre Poilievre, who is running to reclaim a seat in Canada's parliament next week, was on track to be prime minister until Donald Trump upended Canadian politics.

But even if the Conservative Party leader wins Monday's by-election in one of the country's most right-wing districts, experts say he may struggle to regain momentum in a political arena still heavily shaped by the U.S. president.

Poilievre's Conservatives blew a massive polling lead in the run-up to Canada's April general election, as voters backed the new Liberal leader, Prime Minister Mark Carney, to confront Trump.