The governing Liberals are making a last-minute push to get their supporters to cast ballots in Thursday's by-election races as disgruntled teachers defect to the New Democrats.
In the Southern Ontario riding of Kitchener-Waterloo, where the Liberals are in a tight three-way race with the NDP and the Progressive Conservatives, the outcome will likely depend on which party does the best job of getting people out to vote.
A senior Liberal insider acknowledged that those who are angry at the government are the most motivated to vote.
The motivated voters include elementary and secondary school teachers, who helped the Liberals win three consecutive provincial elections.
But with the government locked in a protracted fight with teachers over their contract and proposed legislation that would freeze their wages for two years, it can no longer count on their support.
"Many who voted for us won't vote for us," the insider said. The challenge for the Liberals, he said, is actually getting party supporters to the polls, particularly in Kitchener-Waterloo.
The Liberals are widely expected to hold onto the riding of Vaughan, north of Toronto, a stronghold since 2001.
Despite a recent survey by Forum Research showing the NDP set to win in Kitchener-Waterloo, the Liberal insider said the race remains a "crapshoot."
Premier Dalton McGuinty was in Waterloo Wednesday evening, where he urged campaign workers to "leave no door unknocked."
Mr. McGuinty's push to rein in public-sector wages has played well with many members of the public. But it could turn out to be a risky strategy in Kitchener-Waterloo, a one-time blue-collar riding that is now home to thousands of public-sector workers at its two universities, as well as public schools and hospitals, said political scientist Peter Woolstencroft, who teaches at the University of Waterloo.
"I can't imagine there are many public sector workers who will happily vote Liberal," he said in an interview. "They're drifting clearly to the NDP."
The trend is most apparent with teachers.
Greg Weiler, president of the Elementary Teachers' Federation of Ontario's Waterloo region, said his members are throwing their support behind NDP candidate Catherine Fife. As the former president of the Ontario School Boards Assocation, Ms. Fife is well-known to teachers, Mr. Weiler said.
"Before I even sent out anything to our members, teachers were volunteering for her campaign," he said.
A victory in Kitchener-Waterloo would be a game-changer for the Liberals.
Veteran Progressive Conservative Elizabeth Witmer resigned as MPP for the riding in April, after Mr. McGuinty appointed her chair of the Workplace Safety and Insurance Board.
The Liberals were re-elected last October with just one seat shy of a majority.
A win in Kitchener-Waterloo could hand them a de facto majority in the 107-seat legislature.
The Speaker, who can only vote if there is a tie, traditionally sides with the government.