A tight three-way race among the federal Conservatives, Liberals and NDP has raised the possibility of a coalition forming government after the Oct. 19 vote.
Various campaign polls have suggested that whichever party does take the most seats in the election will almost certainly only have a slight minority — opening the door for a coalition to step in.
Both the Liberals and NDP have made it clear that removing the Tories from power is their top priority, but their leaders have offered contrasting takes on how open they would be to forming a coalition to achieve that goal.
While informal alliances struck for political expediency are commonplace — such as when parties vote in step to ensure that a budget passes — a formal coalition is another story entirely.
There has only been one federal coalition in Canadian history. It came during the tumultuous years of the First World War, when the issue of conscription divided Sir Wilfrid Laurier’s Liberals, resulting in an overwhelming majority for Sir Robert Borden’s Unionist party in the election of December 1917.