MONTREAL - A war of letters has erupted within the Parti Quebecois.

The epistolary conflict breaks into two camps: ex-premier Jacques Parizeau, who is adored by the party's hardline wing, against supporters of the party's current leader Pauline Marois.

Parizeau penned an open letter Tuesday that essentially mocked an earlier one, published by a group of young MNAs, that asked him to stop being so critical of their party.

Parizeau's letter began with a tongue-in-cheek suggestion that this self-declared youth movement wasn't actually so young.

He noted that some of his detractors were well over 40 -- an age at which, he pointed out, party founder Rene Levesque had already nationalized hydroelectricity in the 1960s.

"At that age, I'd already worked with three consecutive premiers and, if you'd have described me as the 'young' president of the Parti Quebecois' national executive, I'd have taken it," Parizeau wrote.

"Back in those days, we used to call 40 years the age of experience."

He also said that, as a citizen, he has every right to be critical of the party and the way it has handled issues like the pursuit of independence and the Quebec City arena project.

Parizeau's wife, MNA Lisette Lapointe, was among four people who quit the party caucus last week and chose to sit as Independents.

The four expressed several frustrations, partly over the go-slow approach to Quebec independence but especially over the gag order slapped on MNAs who felt uneasy with the party's unblinking support of the Quebec City arena project.

The members refused to back a PQ-sponsored bill that would essentially have quashed any lawsuit against the untendered arena-management deal between Quebec City and media giant Quebecor.

"Playing out beyond this incredible political comedy was the drama of those who refused to be muzzled and to betray their principles; they demanded their freedom of expression," Parizeau wrote.

"And after all this mess, you essentially come and demand that I keep quiet! How could you believe for an instant that I would comply? I don't intervene often; in fact, (I do it) less and less often.

"I don't abuse my right to speak -- but I demand it. There is no ageism or 'youthism' when it comes to freedom of speech. We are all citizens."