International Relations Minister Jean-Francois Lisee confirmed the news late Friday.
"I wish Mr Boisclair good luck in these difficult times and I thank him for the excellent work he has accomplished in the last few months in New York," Lisee said in a statement.
Boisclair has scheduled a news conference in Montreal on Monday.
Earlier on Friday his boss was less than categorical in her support for Boisclair.
Premier Pauline Marois was asked whether she still had confidence in him.
"Mr. Boisclair is a responsible man," she told a news conference in La Malbaie, Que.
"I am certain he will know to make the decisions that need to be made at the appropriate time."
That choice of words was similar to what Marois said about former Montreal mayor Gerald Tremblay last year, before he resigned in scandal. Tremblay has since cited Marois' comments as the moment he knew he needed to quit, because the provincial government was forcing him out.
A former construction boss has testified at the Charbonneau Commission into Quebec's construction industry that Boisclair authorized a $2.5-million subsidy in 2003 for a project involving a company that had ties to the Hells Angels.
Boisclair was a PQ cabinet minister when he gave the green light to the subsidy just days before a provincial election won by the Liberals.
Jacques Duchesneau, a Coalition member of the legislature, drew links this week between the criminal organization and the fact Boisclair has admitted to using cocaine before.
He made dark suggestions that Boisclair's drug use might have left him at the mercy of the criminal group and made him feel pressure to offer the contract.
Given that Duchesneau was a former police investigator and head of the provincial anti-collusion unit, that left Quebecers wondering whether he actually knew something about Boisclair — or whether he was engaging in a smear job.
Duchesneau has played coy, declining to say whether he holds any incriminating information.
Boisclair then threatened Duchesneau with legal action if he didn't retract his comments. Duchesneau in turn said he had no intention of withdrawing the remarks.