Prime Minister Mark Carney announced six byelections Sunday, with voters in three Quebec ridings, two Ontario ridings and one Saskatchewan riding set to head to polls Dec. 7.

The byelection in Montreal’s Laurier—Sainte-Marie riding will replace longtime Liberal MP and former environment minister Steven Guilbeault, who stepped down in August over his opposition to Carney’s environmental policies.

In Rosemont—La Petite-Patrie, also in Montreal, a weakened NDP will seek to keep control of the riding after its last Quebec MP quit to run for provincial office. Alexandre Boulerice, who represented the riding since 2011, is now Québec solidaire’s MNA in Gouin, which overlaps with his old federal riding.