A proposal to help clear the way for a re-entry of the Pike River coal mine by Labour has been labelled "dangerous and contradictory" by the Government.
Environment Minister Nick Smith said Labour leader Andrew Little's proposal to change the law to exempt Solid Energy from health and safety laws was hypocritical and unsafe.
"It would be extraordinary to make an exemption from the Health and Safety at Work Act from the very place where 29 workers lost their lives from inadequate standards that triggered the new law," Smith said.
"Based on the advice I have received, I remain very doubtful of claims that the mine can be safely re-entered. The mine has 100,000 cubic metres of methane and is likely to have residual heat sources capable of triggering an explosion if there was a source of oxygen."
New Zealand First leader Winston Peters welcomed the "change of heart" shown by Little.
"Little is right to follow New Zealand First's view that Parliament is the master of its own destiny and if there is a legal impediment then we can change that within an hour."
Little said yesterday he would table a bill in Parliament on the first sitting day in February which would assist the families in their bid to access the West Coast coal mine's drift.
Prime Minister Bill English has said health and safety laws which were introduced in response to the Pike River disaster in 2010 make any re-entry all but impossible.
During his visit to Greymouth, Little said he had a solution.
"We can actually deal with that threat of liability for the [Solid Energy] directors by legislating to prevent that happening in this particular case.
"What I pledged to the families is that on the first day of Parliament I will seek leave to table a bill that does just that."
He added: "It removes any risk of liability for the directors of Solid Energy in relation to any attempt at re-entry for the purpose of recovering remains or any bodies in the drift leading to the mine.
"And I'm working on that bill now, I'll have that ready to go on the 6th of February."
The Pike River families commissioned a report from international mining experts last year which concluded that a safe re-entry was possible. They say re-entering the 2.3km drift could not only allow recovery of any remains but provide more evidence about the cause of the disaster.
The mine has been closed since November 2010 after a gas explosion killed 29 workers.
Speaking in Parliament last year, English said Pike River was the "most dangerous workplace in New Zealand", and approving a re-entry would go against the very health and safety laws passed by Parliament in response to the disaster.
English said Little himself had lobbied for the safety changes.
"The member should understand the legislation which he advocated for, which brings together judgement about safety and legal responsibility for anyone in that workplace," he said.
"So whatever any independent expert says, someone who is responsible for anyone who might go into that mine are legally responsibly for their lives."
Peters has also committed to re-entering the mine, saying it will be a condition of any coalition negotiations after the election.
A former miner, Peters has even promised to go into the mine himself, saying he was "offering to be on the first party back in."