The division of the territory for electoral purposes must respect a basic democratic principle: the effective representation of electors. The Act respecting elections and referendums in municipalities (Chapter E-2.3) provides for a number of rules making it possible to ensure effective representation. The equality of the votes of electors and respect for natural communities are the two fundamental criteria set out in this Act.
The equality of the votes of electors is an important prerequisite for effective representation. Each electoral division must have roughly an equal number of electors.
However, this equality is relative as variations in relation to the average number of electors per electoral division are allowed. Under the Act, the number of electors in an electoral division must deviate by not more than 25% from the average.
The equality of the votes of electors alone cannot guarantee effective representation. Electoral divisions must represent natural established communities based on geographic, demographic and socioeconomic criteria.
The electoral divisions must thus be delimited in a way that ensures the greatest socioeconomic homogeneity possible of each, taking into account criteria such as the location of educational institutions, physical barriers, population trends, municipality boundaries, territorial contiguity, size and distance. Furthermore, as far as possible, an electoral map must take into consideration the population's attachment to its community.