OTTAWA – The NDP are calling for a parliamentary investigation into Liberal MP Nicola Di Iorio's delayed resignation, arguing that his explanation for not being in the House of Commons isn’t "suitable" and his absence is taking away his constituents' rights to representation in Ottawa.

NDP MP Nathan Cullen rose on question of privilege Monday afternoon in the House of Commons, where he presented his case for why he thinks Di Iorio's absence merits a fulsome study by the Procedure and House Affairs Committee.

Di Iorio announced earlier this month that he intends to resign his seat in the House of Commons, effective Jan. 22, 2019. This came after questions were raised as a result of his prolonged absence from Parliament Hill.

The rookie MP first declared back in April that he would be leaving politics, citing family reasons, but never resigned his seat. He then said in the fall that he was taking time to contemplate his political future. As he was doing that, Di Iorio hadn’t been seen in his seat in the House of Commons, but he had made appearances in his capacity as a lawyer.

Cullen argues that without taking any steps to actually vacate his seat, and still receiving the salary and benefits that come with being a member of Parliament, Di Iorio's behaviour contravenes a parliamentary rule that states that every MP is bound to attend sittings in the House unless busy doing other official or parliamentary business outside of Ottawa.

"That is not the case to the best of our knowledge with the member from Saint-Leonard-Saint-Michel," Cullen said in the House.

As part of his most recent vow to resign in the new year, Di Iorio said he planned to wrap up projects in his riding—which he claims Prime Minister Justin Trudeau approved—and would serve his constituents from home.

"We find this quite extraordinary," Cullen said.

MPs receive a $172,000 salary but after being absent for 21 days, they can have $120 a day clawed back each day following. It is unclear whether Di Iorio has had his pay docked as a result of his absence.

According to The Canadian Press, Liberal Whip Mark Holland said that the Montreal MP will "donate his salary back" between September and his January resignation.

Cullen said his concern is that by refusing to resign his seat or return to the Hill, Di Iorio is denying his constituents representation. Cullen questioned whether Di Iorio's continued absence from votes and debates may be a contempt of Parliament.

He thinks the matter needs to be further investigated, specifically by referring it to the Procedure and House Affairs Committee. He suggested that should the committee determine action is needed and his reasons for not being on the Hill aren't valid, Di Iorio be suspended or expelled from his seat, "to maintain the authority and dignity of Parliament."

"If we allow this type of behaviour to go not considered, if we as members of Parliament simply say 'this is fine' that an MP can take their seat duly elected from their constituency, and then just simply not show up for work, still receive pay… and we as members of Parliament, you as Speaker, and us as the House simply say 'that's fine,' then essentially we’re condoning that behaviour," Cullen said.

Conservative MP Mark Strahl supported Cullen’s request, saying this is "truly an exceptional circumstance and I think that we need to deal with it in that manner."

The Speaker of the House of Commons took their points under advisement and will come back to the House with his decision whether or not to approve the study, at a later date.

CTVNews.ca has reached out to Di Iorio for comment.