Parti Québécois leader Pauline Marois has expelled Blainville, Que. MNA Daniel Ratthé from the party's caucus over his interest in the province's newest political party.

Marois said she could not tolerate discussions Ratthé is apparently having over possibly joining the Coalition Avenir Québec (CAQ).

"I cannot put my confidence in a member whose convictions are swayed by opportunism...I cannot accept a member remaining in the heart of our political party while considering joining the Coalition Avenir Québec," said Marois in a statement released late Thursday morning.

Former Parti Québécois cabinet minister François Legault officially launched the CAQ, a centre-right political party, earlier this month.