Prime Minister Jacinda Ardern says National "rejected" plans for a virtual Parliament, leaving her with "no option" but to allow a physical sitting of MPs.
"The question for us was whether or not we could actually, as we've asked everyone, to find ways to do things that don't require travel, to work online if you can," Ardern told The AM Show on Tuesday.
"We had, with the National Party, worked up an online option to replace QuestionTime, because that's the thing that we have been missing. We've still had select committees but we haven't had Question Time.
"We came up with an online option. The National Party rejected it and that's why the House is now convening. I personally don't favour the House convening, but I feel like I have no option."
National leader Judith Collins and ACT leader David Seymour both support a physical sitting of MPs this week, albeit a much slimmed-down version. It will be the first sitting of Parliament under alert level four.
But the Greens and the Māori Party are refusing to show up, both accusing National and ACT of unnecessarily putting people at risk during a COVID-19 outbreak.
"We believe it is our role as leaders to lead by example, to continue practicing alert levels 3 and 4 and proceed with caution in order to protect our whakapapa," said Māori Party co-leader Debbie Ngarewa-Packer.
"National and ACT are putting us all at risk, and it wreaks [sic] of white privilege."
Greens co-leader Marama Davidson added: "National and ACT are selfishly choosing to risk the lives of our whānau and communities for political posturing."
Seymour's office said he is the only ACT MP who will be in Parliament and will have no staff onsite. He has been in Wellington since the start of lockdown, has had a saliva test as a precaution which was returned negative, and is double vaccinated.
Collins is also fully vaccinated.
According to the POLITIK website, National's former Shadow Leader of the House Chris Bishop had been working on plans - as a member of Parliament's Business Committee - to establish a virtual sitting of MPs this week.
But Bishop was apparently left in the dark about plans to oppose it, with Deputy Shadow Leader of the House Michael Woodhouse telling the Business Committee National would not agree to the proposals.
Bishop has since been stripped of his Shadow Leader of the House role, which Collins has given to Woodhouse.
There was speculation Bishop lost the portfolio after suggesting he didn't agree with National opposing the Government's law to ban conversion therapy. But Collins told Magic Talk it was because she wanted him focused on his COVID-19 response portfolio.
Collins told Magic Talk if Ardern can host daily press conferences in person, then Parliament should be able to convene too.
"She has a physical press conference every day in the theatrette in Parliament with the Press Gallery all there sitting a couple of seats apart from each other, and that's perfectly fine," she said.
"As soon as we say we want some accountability from the Prime Minister from people who really will ask the questions, like myself, no she doesn't want that."
Collins wants the Epidemic Response Committee reinstated, a virtual group of MPs established during the April 2020 lockdown to be a substitute for both the House and select committees.
It was chaired by then-Opposition leader Simon Bridges and was televised. If brought back, it could provide a platform for Collins.
"Why has that not been brought back? It was a very robust process and it led to some very good scrutiny and some better outcomes and answers than we ever get out of Parliament," Collins said.
"The Prime Minister has steadfastly refused to have that level of accountability, and the reason is of course because I would be chairing that, not Trevor Mallard, her friend."