Ontario by-election · September 3, 2026

The fortress predates her.

Doly Begum resigned in February 2026 to run federally — for the Liberals — and won in April. It is tempting to read the New Democrat share here as hers. The record says otherwise: the seat ran more than 22 points ahead of the provincial NDP before she was ever on the ballot.

Writ issued · polling day set

Live results

Connecting to the official count…

Preliminary results · Elections Ontario

The Vote-Scope forecast

Projected vote share (10th–90th percentile, median marked)

Fatima Shaban Ontario NDP

40.6 % Chance of winning: 74 %

Ahsanul Hafiz Ontario Liberal

29.3 % Chance of winning: 19 %

Noor Tarun Progressive Conservative

27.7 % Chance of winning: 6.9 %

Mark Bekkering Ontario Green

1.8 % Chance of winning: < 1 %

Only two points are stripped: her first election produced the smallest New Democrat premium on record, which is hard to read as a personal effect. One risk is deliberately left unmodelled — Begum did not merely leave, she joined the Liberals and won under their banner. Some of her personal following may follow that move to the Liberal candidate, but nothing in the record lets us size that yet.

The local poll

Ontario Liberal

43 %

Progressive Conservative

29 %

Ontario NDP

19 %

Undecided

22 %

Mainstreet · 2026-03-31 · n=464

The published toplines include 22 % undecided; they are redistributed in proportion to expressed intentions, no breakdown having been released.

This poll is not averaged onto the model afterwards: it is anchored inside the riding's baseline, where it carries about < 1 % of the weight before the simulation runs. Its information then flows through the national draws, the estimated correlations between parties and the local swing elasticities. The weight rises as further polls arrive, with their sample size and recency.

A single firm, a single wave. Sample size, margin of error and collection method were never published. Treated with wide uncertainty.

How this projection is built

Personal vote removed

2 points stripped from the Ontario NDP baseline — the share that belonged to Doly Begum rather than to the party.

43.1 % → 41.1 %

2025 result — the seat as it was won

Ontario NDP 42.9 %

Progressive Conservative 30.6 %

Ontario Liberal 22.9 %

Ontario Green 3.5 %

41.7 %

Why this by-election exists

Begum, NDP MPP since 2018, stepped down in February 2026 to run for the Liberals in the federal Scarborough—Southwest by-election, which she won on April 13, 2026 with 69.6%.
New Democrat share versus their province-wide score: +22.0 points (2011) and +23.0 (2014) — years before she was elected.
Under Begum: +12.1 (2018, her first election and the LOWEST premium on record), +23.9 (2022), +24.4 (2025).
Four candidates are named: Dr. Noor Tarun (PC), Ahsanul Hafiz (Liberal), Fatima Shaban (NDP) and Mark Bekkering (Green).

Sources