What is electoral redistribution in Canada?

Electoral redistribution is the decennial process of redrawing federal riding boundaries in Canada to reflect changes in provincial populations and internal population shifts. Redistribution is conducted by 10 independent provincial Electoral Boundaries Commissions appointed under the federal Electoral Boundaries Readjustment Act of 1985. The Commissions are typically chaired by a provincial judge and include two other independent members appointed by the Speaker of the House of Commons.

The redistribution process follows the federal census every 10 years. After the 2021 federal census, redistribution proceeded between 2022 and 2024, producing the new 343-seat House of Commons that took effect for the April 28, 2025 federal election. The previous 338-seat allocation had been in effect since 2015. Each province's seat allocation is calculated using the federal Constitution Act, 1985 formula, which is based on the provincial population's share of the national population, subject to several constitutional minimums.

Two constitutional rules protect smaller provinces. The 'Senate floor' rule (section 51A of the Constitution Act, 1867) ensures that no province has fewer MPs than its number of senators (which gives Prince Edward Island its constitutional minimum of four MPs, though its population would otherwise warrant only one or two). The grandfather clause (section 51(1) of the Constitution Act, 1867, added by the 1985 amendments and reaffirmed by the Preserving Provincial Representation in the House of Commons Act of 2022) ensures that no province has fewer MPs than it had in 1976. After the 2021 census, the grandfather clause prevented Quebec from losing a seat (Quebec retained its 78 seats rather than dropping to 77).

Each provincial Boundaries Commission produces a draft of new riding boundaries, holds public hearings, considers submissions, and issues a final report. The reports are reviewed by the House of Commons Standing Committee on Procedure and House Affairs, which can recommend (but not compel) changes. The Commissions then issue final boundaries, which are proclaimed and take effect in time for the next general election. The 2024 redistribution gave Ontario 122 seats (up from 121), Quebec 78 (unchanged due to grandfather clause), British Columbia 43 (up from 42), Alberta 37 (up from 34), Manitoba 14 (unchanged), Saskatchewan 14 (unchanged), Nova Scotia 11 (unchanged), New Brunswick 10 (unchanged), Newfoundland and Labrador 7 (unchanged), Prince Edward Island 4 (unchanged), and 1 each for the three territories.