Voters in two Ontario ridings and one in Quebec will head to the polls on Monday for a slate of crucial federal byelections that could hand the Liberals a majority government — cementing their hold on power for the next few years.

The Liberals need to win just one of those races to secure a razor-thin majority government. Because the Speaker of the House is a Liberal MP, winning two or all three would give the party more control of House business.

It would also give Prime Minister Mark Carney more runway to implement his agenda, moving the next scheduled election to 2029.

The Ontario ridings up for grabs, University—Rosedale and Scarborough Southwest, are considered safe Liberal seats. The Liberals won the Quebec riding of Terrebonne by just one vote over the Bloc Québécois during the spring 2025 election.

The Supreme Court of Canada annulled the election result in that Montreal-area riding.

Prime Minister Mark Carney and his team have avoided making any public assumptions about the outcome of the three races, but the Liberals have said a majority government would allow them to implement their agenda faster.

Last week, government House leader Steven MacKinnon said that in the event the Liberals win a majority, the federal government will “continue that impulse of working across party lines” even if it’s not required to co-operate to pass legislation.

The Liberals’ quest for a majority became easier last week after they picked up another Conservative floor-crosser, Ontario MP Marilyn Gladu. Her decision to break ranks brought the Grits to 171 seats in the House of Commons.

CBC News will have special coverage of the three byelections, hosted by chief political correspondent Rosemary Barton, beginning at 8 p.m. ET. You can watch the coverage here.