Boisclair says he has asked his lawyers to take Jacques Duchesneau, his opposition Coalition party and the party's Francois Legault to court for damaging his reputation.
"Since Wednesday, I have been dragged through the mud because of a no-holds-barred brand of partisan politics," Boisclair said at a news conference Sunday.
"I have never had a debt towards organized crime and was never pressured by organized crime."
Last week, a former construction boss at Quebec's corruption inquiry alleged Boisclair authorized a $2.5-million subsidy in 2003 for a project involving a company, LM Sauve, that had ties to the Hells Angels.
That led Duchesneau to wonder aloud whether there was a possible connection between Boisclair's past drug use and the granting of the subsidy just before a provincial election won by the Liberals. Boisclair was a PQ minister at the time.
"I am making a link between the $2.5 million, someone associated with the Hells Angels, and someone who consumed (drugs) and made decisions,'' Duchesneau told reporters last Wednesday in outside the legislature chamber in Quebec City, before making similar remarks in TV interviews.
"So that, and other questions too, will be asked at the opportune time."
"In 2005, Mr. Boisclair himself admitted that he used cocaine while he was a (cabinet) minister. So the question is: with Mr. Sauve being associated with the Hells Angels, and a subsidy of $2.5 million being granted, did that influence his (Boisclair's) decision? I don't know.''
Boisclair says he has known the former construction boss, Paul Sauve, for many years but that the funding to repair a Montreal church followed the rules.
On Sunday, spokesman for the Coalition said the party would await legal notice and not comment for the moment.
Boisclair asked to be temporarily relieved of his duties as Quebec's official representative in New York City on Friday in order to fight what he called "petty and dishonest connections" made by Duchesneau.
Prior to Boisclair's news conference, PQ Premier Pauline Marois tried to steer clear from the controversy at an unrelated announcement in Montreal on Sunday.
"Mr. Boisclair is a responsible man; he's the one who asked to be relieved of his duties in order to defend himself, and I'm sure he'll take the necessary actions to do this," she told reporters.
Boisclair became leader of the PQ after his party lost the 2003 election. He left politics after losing the 2007 election and was appointed to his diplomatic post in 2012.
Duchesneau, a former police chief, previously worked for the government anti-collusion unit under the Quebec Liberals.
Also on HuffPost