Residents in the Quebec riding of Marie-Victorin on Montreal's South Shore will head to the polls on April 11 to choose their new provincial legislature member.

Premier François Legault called the long-awaited byelection for the seat on Tuesday, following a special cabinet meeting.

"Quebec's lockdown ends in a few days and all the candidates will be able to meet voters without restriction. It's good for Marie-Victorin, it's good for democracy," Legault said in a statement.

Opposition parties have been calling on Legault to call the byelection for some time, insisting all the candidates have already been presented and the unofficial campaign is already underway.

They accused the Coalition Avenir Québec party of dragging its feet and putting its own partisan interests ahead of those of the population. Legault blamed the delay on the pandemic.

The seat in Marie-Victorin, long a Parti Québécois stronghold, was left vacant by Catherine Fournier, who won the riding with the PQ in 2018, then quit the party to sit as an independent and finally resigned from provincial politics entirely when she was elected mayor of Longueuil last November.

Legault's party is running Shirley Dorismond, a nurse who works in addictions and mental health, against PQ candidate Pierre Nantel, who represented the Longueuil area as an MP with the NDP. Émilie Nollet, an entrepreneur and university researcher in the field of social inclusion, is running for the Quebec Liberal Party.

Actress Anne Casabonne, well-known for her Quebec television roles, is carrying the message of Quebec's Conservative Party, while 22-year-old mathematics student Shophika Vaithyanathasarma is running for Québec Solidaire.

Former PQ cabinet minister and past Bloc Québécois leader Martine Ouellet will also be running for a new party she founded called Climat Québec.

Legault will hold a news conference with his candidate, Dorismond, on Tuesday afternoon in Longueuil to officially launch the CAQ campaign in Marie-Victorin.