Members of the Parti Quebecois have begun voting for a new leader to replace Pierre Karl Péladeau.
More than 73,200 members can vote by phone or online, until Friday at 5 p.m.
The leadership candidates are members of the legislature Jean-François Lisée, Alexandre Cloutier and Martine Ouellet and the unelected Paul St-Pierre Plamondon.
Recent polls have indicated that Lisée and Cloutier are battling it out for first place, with Ouellet running third and Plamondon languishing in fourth.
The campaign has focused largely on issues of language, identity and Quebec sovereignty.
Only Ouellet has promised to hold a sovereignty referendum in a first PQ mandate should she win and become premier in the 2018 provincial election.
The race for the PQ's top job is the second in less than two years after Péladeau cited family reasons when he quit last May, just one year after he became leader.