Laurier—Sainte-Marie
Federal by-election in Quebec on December 7, 2026, after the departure of Steven Guilbeault (Liberal).
The Liberal Party is the favourite, with a better than 99% chance of winning and 48% of the projected vote.
The forecast
| Party | Projected share | Range (80%) | Chance of winning |
|---|---|---|---|
| Liberal | 48.3% | | >99% |
| NDP | 17.7% | | <1% |
| Bloc Québécois | 16.0% | | <1% |
| Conservative | 12.1% | | <1% |
| Green | 3.8% | | <1% |
| People's Party | 2.1% | | <1% |
There is no local poll. The forecast starts from our current federal projection for the riding, removes 3 points of personal vote from the Liberals, and adds the turnout gap measured at the April 13, 2026 by-elections.
What the forecast adjusts
- Personal vote removed
- 3 points removed from the Liberal vote: the share that went to Steven Guilbeault rather than to the party. 52.0% → 49.0%
The 2025 result
The race
In 2015, before Steven Guilbeault ran here, the Liberals were 12.3 points below their Quebec-wide score. With him they were 8.4 points above it in 2025. Part of that lead is his, and leaves with him.
- Guilbeault left the House of Commons on August 28, 2026 to work on climate change outside Parliament.
- Liberal share compared with the party’s Quebec-wide vote: −12.3 points in 2015 (before him), +6.8 in 2019, +2.8 in 2021, +8.4 in 2025.
- The riding has a strong left vote: the NDP still took 18.6% here in 2025.
The other by-elections on December 7, 2026
| Riding | Favourite | Chance of winning |
|---|---|---|
| Rosemont—La Petite-PatrieQuebec | Liberal | 95% |
| Saint-Hyacinthe—Bagot—ActonQuebec | Bloc Québécois | 72% |
| Yorkton—MelvilleSaskatchewan | Conservative | >99% |
| Brantford—Brant SouthOntario | Liberal | 86% |
| Scarborough NorthOntario | Liberal | >99% |