The Liberal Party of Lester Pearson were ahead of the Tories when the election was called, and it looked inevitable that they would form a majority government.

Ultimately, the Liberals were able to regain the momentum with a platform promising that, if elected, they would begin their term with "60 Days of Decision" on several key questions, while Diefenbaker's repeated attacks on President Kennedy had limited effectiveness.

The Tories' refusal to work with the Socreds also proved damaging, contributing to their losing ground in British Columbia, where they slipped to third place behind the Liberals and NDP.

Kennedy sent his consultant, Lou Harris, to work on the Pearson campaign and General Lauris Norstad publicly criticised the Conservatives for not meeting their NATO contributions.

The Social Credit Party was unable to increase its representation in western Canada, and lost four of its Quebec seats despite gaining a slightly better share of the vote compared to 1962.