The National Party believes the new government is already back-pedalling on its pledge to re-enter the Pike River mine.
Pike River Photo: RNZ
Twenty-nine men died when the mine exploded on the West Coast in November 2010.
In January, the new government will establish a Pike River Recovery Agency - Te Kahui Whakamana Rua Tekau ma Iwa.
It will be charged with devising a plan for a manned re-entry of the mine's drift, to explore 400 metres of it which haven't been searched, and recover any bodies by March 2019.
But the Prime Minister Jacinda Ardern said safety would not be compromised.
"Any decision to re-enter will be based on a thorough technical assessment of the risks and advice on how the risks can be mitigated.
"The families know that we will not endanger any more lives and in fact, that has been one of their most important principles."
The minister responsible for Pike River Re-Entry, Andrew Little, said the new agency would conduct a re-entry risk assessment which would then be peer-reviewed.
But the buck stops with him.
"The decision on whether or not to re-enter will be mine - as the minister - based on the advice that I get from the agency, which as I say will be peer-reviewed and there'll be an independent stream of advice to me as minister in any event."
But the National Party's spokesperson for Workplace Safety and Pike River, Amy Adams, said there's been a considerable shift in the new government's position.
"It seems to me that there's a considerable softening on the position they expressed repeatedly and quite emphatically during the campaign - that they already had clear advice that they could re-enter and that they would be absolutely doing so," Ms Adams said.
"Now it seems what they are saying is far more in line with what the previous government had consistently maintained which is that it absolutely wasn't opposed to a manned re-entry but that it would have to be done in a way which was safe."
But Bernie Monk, who lost his son Michael in the disaster, rejected Ms Adam's criticism and said he was upset by the comments.
"They're (the government) being straight up and down the middle.
"The National government hid behind things the whole way through here, locked our experts out of any negotiations of making this happen and she's a great one to say that. And, I feel a bit hurt by it and offended by what she's saying.
"We all don't want things to happen but we're making sure that all the i's are dotted and t's are crossed and we will get through this - not like the National government's done over the last six years of hiding behind and keeping it all in secrets."
Former chief mines inspector Tony Forster said in the seven years since the disaster, some hazards will have increased, and some will have diminished.
He said previous work towards a manned re-entry was still valid and would inform the decisions "but that's got to be augmented by looking afresh and taking a fresh review of where the current situation lies".
"A lot of the original work is ... extremely useful" - Tony Forster
Mr Little said the Pike River Recovery Agency would also gather evidence to better understand the original disaster, with an aim to preventing similar tragedies in the future.
It has been given a budget of up to $23 million over the next three years and the State Services Commission will recruit its chief executive.