Vacancies
Normally, if a vacancy occurs in a council seat, a by-election is held in the affected ward as early as possible.
If a vacancy occurs after March 31 in the year of a municipal election, however, provincial law prohibits the holding of a by-election so close to a regular election — and accordingly city council solicits applications for a temporary appointment to the vacant seat. Normally, a condition of the application process is that the appointed interim councillor does not run as a candidate in the regular election, so that he or she does not gain an unfair incumbency advantage. There have, nonetheless, been instances in which appointed interim councillors have tested the rule; most recently, Paul Ainslie did so in 2006 by filing as a candidate in a different ward than the one where he had been appointed.
Read more about this topic: Toronto City Council