Those who see Jean Charest as the head of the Conservative Party of Canada should think twice, according to the Parti Québécois (PQ) and Québec Solidaire (QS).

Tuesday, leaders Paul St-Pierre Plamondon and Gabriel Nadeau-Dubois said they have serious doubts about the former premier's integrity after he was reportedly approached to run for Erin O'Toole's seat.

According to numerous reports, Charest is now canvassing support.

At a press conference, QS's Nadeau-Dubois suggested that some "very heavy suspicions" should make people second guess voting for Charest.

"Decades of collusion and corruption documented by the Charbonneau Commission, under his reign, weakens Quebec's democracy significantly, weakens people's confidence in democratic institutions," he said.

For his part, the leader of the PQ says he deplores the fact that all the investigations into corruption and collusion have never held anyone responsible.

St-Pierre Plamondon laments this is the legacy that Charest has left in terms of institutional quality.

"We normalized corruption by trivializing it," he said.

Liberal (PLQ) leader Dominique Anglade has mostly avoided commenting on Charest's possible return to politics.

Many of her current caucus members were loyal to Charest.

"I'm not going to get involved in a leadership race for a federal party," she said.

When asked about his record, she mentioned the "first gender-balanced cabinet," but refused to speak further.

"Once again, we are not here to evaluate Jean Charest's record," she concluded.

According to Nadeau-Dubois, Anglade's discomfort is "palpable" now that she is trying to turn the PLQ into a resolutely progressive party.

"I think that the return of Jean Charest would complicate her task," he said.

Charest was premier of Quebec from 2003 to 2012.

-- This report by The Canadian Press was first published in French on Feb. 15, 2022.