Prime Minister Jacinda Ardern says Labour MPs should have been on time to a select committee hearing this morning that was cancelled, wasting submitters' time.
And while National MPs could have ensured the hearings took place by simply going back inside the room, they said they had no intention of apologising to people whose time was wasted.
The Finance and Expenditure select committee collapsed this morning, with Labour and National MPs blaming each other for the mess.
National MPs walked out of the meeting in protest, accusing Labour of failing to get out of bed on time, while Labour says National MPs were being childish by standing outside the door and refusing to take part.
During the standoff about 15 submitters, some of whom had travelled to Wellington to have their say on the Government's Budget Policy Statement and the Pike River Recovery Agency, waited outside the meeting room - and were eventually told the meeting had been cancelled.
Under Standing Orders, the meeting cannot take place unless a quorum of at least half the members are present within 10 minutes of the starting time.
Ardern criticised Labour MPs for not being at the committee on time.
"They've made mistakes. We need to own that," Ardern said.
"My expectation is they do their jobs. There's no excuses. I've made it very clear this is not acceptable."
Labour MP and committee chair Michael Wood said one Labour committee member was sick, and Labour MP Jo Luxton joined the committee as a substitute 30 seconds after the cut-off time.
But he said the meeting could have gone ahead if the National MPs simply came back into the room.
"There were enough members for a quorum. They were literally standing outside the door."
National MP David Carter continued his attack on Labour MPs this afternoon and said if anyone should apologise to submitters, it should be Labour and NZ First MPs.
"It's not the Opposition's job to maintain quorums at select committee.
"Labour members are lazy and disorganised. We're fed up with being there on time as National members, and watching Labour members saunter in there 5, 10, 15 minutes late.
"This is a lazy, disorganised Government. They don't read their papers. They ask inane questions. This is the most important select committee in Parliament."
He said National MPs had warned the committee that they could walk out if Labour members did not show up on time.
"They'll still so disorganised, they could not get their members out of bed to a select committee. Get out of bed and be there."
National leader Simon Bridges stood by the actions of the National MPs.
"It is the Government Members of Parliament who should apologise [to submitters]. No ifs, not buts. They weren't taking the business of Government seriously. We adhered to the rules."
Leader of the House Chris Hipkins, who is not on the committee, said the whole episode reflected poorly on politicians and Parliament.
"It's childish game-playing. There were people who came to Wellington to appear before select committee, and found they had completely wasted their time. It's not good faith. It's not the right way to approach things.
"It's a bad look for the parliament as a whole."