NDP Leader Tom Mulcair says he knew of the misconduct allegations being levelled by two of his MPs against two now-former Liberal Members of Parliament, but he did not go public with the complaints to respect their wishes.

Mulcair said his primary concern was to ensure that the two NDP MPs who were making the accusations got whatever help they needed, “and that their wishes were respected.

"Those wishes included a very strong desire to keep this confidential. This was their request and we were not about to override that and make them victims a second time."

The NDP received “no prior warning whatsoever” from the Liberals that they would go public with the allegations, Mulcair told reporters Thursday that an event in Whitby, Ont.

On Wednesday, Liberals Massimo Pacetti of Montreal and Scott Andrews of Newfoundland were suspended from the Liberal caucus after allegations of what party leader Justin Trudeau called "serious personal misconduct."

Both Pacetti and Andrews deny any wrongdoing.

Trudeau asked the Commons speaker to investigate, saying the days when such incidents were dealt with quietly in Parliament's backrooms are long gone.

Trudeau said he had a “duty to act” when he was approached with the allegations.

“I just know that for someone to come forward to a party leader that is not their own, there is an expectation that there will be consequences,” Trudeau told reporters Thursday.

One of the NDP MPs approached Trudeau with allegations of inappropriate behaviour by Pacetti and Andrews on a five-hour bus trip back to Ottawa from Cpl. Nathan Cirillo’s funeral in Hamilton, Ont., last Tuesday.

Details of the allegations have not been made public.

The Liberal and the NDP party whips have met with the alleged victims separately to hear their stories.

CTV News has learned that one of them told of an incident that happened off Parliament Hill about a year ago, while the other alleged victim recounted in detail events that happened months ago, both on and off the Hill.

Speaker Andrew Scheer issued a statement Wednesday to say that he is taking the situation “very seriously” and has directed House Administration to “make available all internal resources to the individuals involved.”

Scheer has also directed the House of Commons’ secretive Board of Internal Economy to take up the matter “at the earliest available opportunity.”

The Liberals have asked that an investigation be opened by an independent third party.

“It’s important that all MPs involved have the opportunity to speak to the allegations,” Liberal Whip Judy Foote told CTV’s Canada AM from Ottawa.

Earlier Thursday, NDP Deputy Leader Megan Leslie said she was not surprised to hear allegations that two Liberal MPs may have behaved inappropriately towards two female members of Parliament. But she said she was "shocked" the Liberals chose to violate the women's privacy by announcing it.

"This is a workplace. People forget that. Just like any other workplace, you're going to have all kinds of issues, including sexual harassment," she told Canada AM from Ottawa.

"I was not surprised to hear the allegations," she said before adding, "I was shocked that the Liberals announced it. I was extremely disappointed that they announced it. I don't believe that they had the right to do that."

In Leslie’s view, making the allegations public means the women are no longer in control of their story.

"It's not up to someone else to decide what a woman needs in this situation. It's up to her. And if she needs space and privacy, then we have to respect that," she said.

Leslie concedes news of the suspensions would have come out one way or another, but she says the Liberals "could have dealt with it in a different way." That way, she says, the announcement would have been about their MPs, "not about ours."

Foote said Thursday that Trudeau had “no choice but to act” given the seriousness of the allegations. One of the two complainants brought the allegations directly to Trudeau, she said.

Leslie said she welcomes the national discussion revolving around issues of consent, rape culture, and harassment that has emerged in the wake of allegations involving fired radio host Jian Ghomeshi.

"It's an amazing conversation and I think what's happening right now is a continuation of that conversation. And it's really important," she said.

"However," she added, "if those two women wanted privacy, they have the right to have that respected."

With a report from CTV’s Deputy Ottawa Bureau Chief Laurie Graham