OTTAWA -- Prime Minister Justin Trudeau offered "unreserved apologies" Wednesday for Parliament's recognition of a man who fought for a Nazi unit during the Second World War and said the Canadian government has reached out to Ukrainian President Volodymyr Zelenskyy in the wake of the incident.

"This was a mistake that has deeply embarrassed Parliament and Canada. All of us who were in this House on Friday regret deeply having stood and clapped even though we did so, unaware of the context," Trudeau told reporters on his way into question period, indicating his plans to personally address the House of Commons about the controversy for the first time since it exploded.

He called the incident a "horrendous violation" of the memory of the millions of people who died in the Holocaust and said it was "deeply, deeply painful" for Jewish people, as well as members of the Polish, Roma, and LGBTQ2S+ communities who were also "targeted by the Nazi genocide."

"Every year, there are fewer and fewer Holocaust survivors to share firsthand the horrors of what they experienced. And it is therefore incumbent upon us all to ensure that no one ever forgets what happened," Trudeau added before entering chamber to offer similar remarks.

It was the first time the prime minister personally addressed the House of Commons about the controversy since it exploded.

Anthony Rota resigned from the House Speaker position Tuesday, the result of all-party pressure for him to do so after he invited, recognized and led the chamber in a standing ovation for 98-year-old Ukrainian veteran Yaroslav Hunka, who fought in a volunteer unit under Nazi command, calling him a "hero."

Facing a series of pointed questions about the internationally-condemned situation that transpired during Zelenskyy's address last Friday, Trudeau noted the Speaker was "solely responsible" for Hunka's recognition.

Still, Trudeau said Canada is "deeply sorry" for the position this has put Zelenskyy and the Ukrainian delegation in, calling it "extremely troubling" that such an egregious error, and the images captured of the moment, are being used as propaganda by Russia and its supporters to amplify false narratives about what Ukraine is fighting for.

"Friday's joint session was about what Canada stands for, about our steadfast support of Ukraine’s fight against Putin's brutality, lies and violence. It was a moment to celebrate and acknowledge the sacrifices of Ukrainians as they fight for their democracy, their freedom, their language and culture, and for peace. This is the side Canada was on in WWII, and this is the side we are on today," said the prime minister.

While Rota's resignation calmed some of the initial acrimony, Conservative Leader Pierre Poilievre and NDP Leader Jagmeet Singh were among those pushing for Trudeau to heed requests from Jewish advocacy groups for a personal apology, noting that it wasn't enough for the Canadians who were feeling the shame the mistake had caused.

In question period, Singh questioned why it took Trudeau so long to say sorry, while Poilievre said Trudeau's apology on behalf of the country didn't go far enough.

The Conservative leader repeatedly called on the prime minister to take personal responsibility for his "personal failure" to vet all attendees, despite the Speaker's guest list not being shared with PMO in advance, per parliamentary protocol.

For events such as parliamentary addresses, each party in the House is granted a certain allotment of invitations and while a central protocol office compiles those submissions to send the invites, the lists are not shared between parties, but are shared with corporate security to facilitate accreditation, according to the Speaker's office.

"When foreign heads of state come here they expect that they will be protected, not only against security threats, but against massive global scale embarrassments and shames like the one he allowed to unfold before Canadians. So, will the prime minister commit to personally calling President Zelenskyy?" Poilievre asked.

While the prime minister did not directly address this question about calling Zelenskyy, his office told CTV News that apologies were made to the Ukrainians at the "ministerial level."

In the moment, the prime minister instead clapped back, questioning why Poilievre has not apologized for a trio of his MPs meeting with far-right German politician Christine Anderson earlier this year.

"If the leader of the Opposition wants the government to help him vet those his MPs meet with, we'd be more than happy to give him some better advice," Trudeau said.

In other responses, the prime minister said it would be egregious if the executive branch infringed on parliamentary privilege in the way Poilievre was suggesting, noting how as a long-time MP and former democratic institutions minister, the Conservative leader should know better.

Asked ahead of Trudeau's remarks whether a further apology on behalf of the nation is required, Liberal MPs didn't directly answer. Immigration Minister Marc Miller suggested Canada's "really dark history" and the presence of Nazi war criminals needs to be reckoned with, while Health Minister Mark Holland implored calm over a continued politicization of this "absolutely massive mistake … that set back the cause of democracy."

In addition to an apology, B'nai Brith wants the government to "take this opportunity to finally open all Holocaust-related records to the public." This would include the full final report of the Deschenes Commission of Inquiry on War Criminals that remains largely redacted but includes intel on Canada's post-war admittance of Ukrainian members of Adolf Hitler's Waffen-SS.

The Friends of Simon Wiesenthal Center (FSWC) has called for the Procedure and House Affairs Committee to launch public hearings to investigate the vetting failures and measures needed to ensure a similar incident does not happen again. 

This is a proposal one of the first-out-of-the-gate candidates to be Canada's new Speaker is championing.

"I think we have to completely look at how the individual made it into the into the gallery, and how it was missed so that it doesn't happen again," Conservative MP and deputy Speaker Chris d'Entremont said Wednesday, confirming his intention to run and pitching what his vision would be should he secure the promotion.

Even with Rota holding the title of Speaker until the end of the sitting day, he will not be in the big chair presiding over House proceedings on Wednesday as the jockeying to replace him has already begun.

"There has to be some more decorum in the House, some more respect for one another,"d'Entremont told reporters on Parliament Hill Wednesday morning, adding that talks are underway among the opposition parties to try to see an opposition MP elected Speaker, given their combined leverage over the minority Liberal government.

There will be Liberals entering the race as well—typically all MPs except for ministers and party leaders are eligible and automatically considered candidates unless they take their name off the list—among them, MP Greg Fergus. In a brief pitch on his way out of Wednesday's Liberal caucus meeting, he spoke about the need to uphold the rules and traditions of the House that allow for frank and passionate, but respectful, debates.

Late Tuesday, MPs agreed that instead of having the deputy Speakers continue to share responsibility for chairing House proceedings in the interim, Bloc Quebecois MP and Dean of the House Louis Plamondon will take over once Rota's resignation is in effect.

That means Plamondon will be in the Speaker's chair during proceedings on Thursday and Friday. Then when the House resumes on Tuesday, Oct. 3 following a long weekend on account for the National Day for Truth and Reconciliation, the first order of business will be the historic secret ranked ballot election of a new speaker.

"We're in a very partisan time. We've had something that hasn't happened more than once in the history of this of this House where the Speaker has resigned for a very specific, emotional reason. And, to try to bring that pressure down is difficult for anybody that's going to be running," said d'Entremont, reflecting on the unprecedented nature of this moment in Canadian politics.