National is accusing the government of winding down its pre-election promises to re-enter the Pike River mine.
It says the plan announced on Monday - manned re-entry by March 2019 depending on risk assessment - is very similar to its own approach when it was in government.
"The government has wound back its promises significantly," said justice spokeswoman Amy Adams.
"It is now recognising that it cannot waive health and safety laws, rush or force re-entry."
Ms Adams says National continues to support re-entry, if it can be safely achieved.
Labour and NZ First made a campaign commitment to re-enter the mine, something the families of the 29 men killed in the explosions have been campaigning for since the 2010 tragedy.
The previous government investigated manned re-entry but decided it was too risky.
It decided instead to use a robot, a plan that's now been scrapped.
The government is going to set up a new department to manage the re-entry under Justice Minister Andrew Little.
"The decision on whether or not to re-enter the mine will be mine, as the minister, based on the advice I get from the department," Mr Little said.
"We will go through the normal risk assessment and hazard assessment steps."
The government is promising the families will be closely involved with the new department, and Prime Minister Jacinda Ardern says no more lives will be endangered.
"There will be risks - our job is to mitigate them as far as possible, and to weigh up whether there is an acceptable level of risk," she said.
The families have welcomed the plan as "a huge step forward".
"After seven years of stalling and being fobbed off by the last government, we're making great strides towards re-entering the drift and recovering remains and evidence," said spokesman Bernie Monk.