After a year of plummeting poll numbers for Canada’s ruling Liberal Party, a shock defeat in a Toronto by-election marked a turning point. The loss in a Liberal stronghold is widely seen as setting off the chain of events leading to Justin Trudeau’s resignation and Monday’s federal election.

The US president came to dominate on the campaign trail, with the contest being viewed as a referendum on how Canada should engage with him.

Donald Trump's annexation threats and tariffs loom large as Canadians head to the polls to pick their prime minister.