Labour MP Gaurav Sharma is expected to be expelled from the party caucus tomorrow, as he continues to level accusations against senior figures, including the prime minister.
Jacinda Ardern is adamant there was no predetermination on Sharma's future.
Ardern told Morning Report the final decision on the Hamilton West MP would be made by caucus tomorrow.
The party tried to keep the door open to allow Sharma to rebuild trust, she said.
"It was a suspension rather than expulsion from caucus ... because there was a hope that we would be able to create a pathway for Gaurav to rebuild trust in his colleagues.
"Obviously, he's made his own decisions. It'll be for caucus to decide."
She said Sharma was invited to present his views at the meeting last week, but he did not show up.
He went public with allegations that he was being bullied. He had formally emailed the prime minister's office in December with detailed complaints against the then-chief whip, Kieran McAnulty.
Ardern said there was no need for an inquiry into his claims.
"All of the allegations that have been made have been refuted, and there's nothing that's been substantiated."
She said there should be a threshold to be able to start an inquiry, especially if "there's no evidence of it".
"In my mind, we've continued to see just repeated unsubstantiated claims, and I think now is the time actually for us to get on with just having that meeting on Tuesday, deciding what that outcome will be.
"I've never predetermined the caucus decision, and I won't start now."
Ardern also refuted Sharma's claims that new MPs were being trained to dodge Official Information Act requests.
"All of the allegations that have been made have been refuted, and there's nothing that's been substantiated" - PM Jacinda Ardern
Nelson floods
Ardern said the stories of the nearly 500 evacuees in Nelson was devastating.
There was additional anxiety about returning home due to repeat nature of such events, she said.
"As we move further into the recovery stage, as we have more geotechnical information, we will have a better understanding of the scale."
Roads between Nelson, Tasman and Marlborough have been damaged.
"We want to make sure that, particularly for isolated communities, that roading network up and running as quickly as possible, but we at this stage don't have soon timelines on some of those issues, let alone the longer term at this early stage."
Speaking to Morning Report from the coordination centre, Ardern said she was waiting to find out how many people were uninsured.
Anyone who self-evacuated is being asked to contact authorities.