In Canadian politics, a leadershipconvention is held by a political party when the party needs to choose a leader due to a vacancy or a challenge to the incumbent leader.
Unlike in the United States, where political conventions are held every four years to choose the party's presidential nominee, in Canada the leader of a party generally remains that party's de facto candidate for Prime Minister until such time as he or she dies, resigns or is dismissed by the party.
Prior to that the leader of the party was chosen by the party's parliamentary caucus.