Prime Minister Bill English has dismissed NZ First leader Winston Peters' calls to re-enter Pike River mine as "just politics" and accused him of misleading the Pike River families.
Speaking in London, English said the key issue was not political, but legal.
"And Mr Peters is misleading the families if he is telling them it is a political decision. If he is willing to become a director of a company and take legal responsibility then I'll take him a bit more seriously."
The comments follow Peters' visit to Pike River yesterday and pledge to make the re-entry of the mine a 'bottom line' in any post-election coalition talks. Peters accused English of being "weak" for refusing to intervene.
English said the safety laws were overhauled after Pike River disaster to ensure someone could be held accountable for safety lapses in future.
"In the end there's no way of avoiding legal responsibility for the safety of anyone who goes in the mine or might go in the mine. Our law allows for prosecution of people making a decision to do something that looks dangerous even before it is done."
Labour leader Andrew Little has also fired back at Peters, saying Peters' comments about being among the first to re-enter the mine were "cheap".
In December Peters said he would be willing to be among the first to enter the drift, and at the public meeting at the Paroa Hotel in Greymouth he also criticised Labour's stance on Pike River.
That drew a response from Little.
"One thing I am never going to be challenged by Winston on is my commitment to Pike River. And the difference between me and Winston Peters is I wasn't sitting in a Cabinet in the 1990s that undermined our health and safety regulations in mine regulations, specifically," Little told the Herald.
"This is a serious issue. Put aside the, I thought, cheap call about Winston leading a team in there - that is disrespectful to the mines rescue folks and others who are experts - you do want the best possible decision to be made."
At today's public meeting, Peters said his party believed in a report that said there is no technical mining reason that re-entry could not be achieved safely.
The report, written by international mining experts and presented by the Pike families, called for the Government to take over ownership of the mine, and for a detailed re-entry plan to be developed.
"We believe your report and believe that a party should be allowed to enter the drift to look for your men," Peters told the meeting.
"And to all those who say we're not serious on this promise, we say, our party will make re-entry into Pike River a bottom line at the next election."
Little has promised that a Labour Government would get an independent assessment of the mine, and re-enter it if it was declared safe.
Peters told the meeting that promise was "weak and disingenuous".
"It means, 'sometime never'. You already have a thoroughly professional report from world-leading experts in this field. How many more reports do the authorities need before they can say 'Go in'? What more proof could they possibly want?"
Little said there were two conflicting streams of advice, and the best way to make a decision was to get an independent report. The Pike River families had accepted that position when he had spoken to them, he added.
The mine has been closed since November 2010 after a gas explosion killed 29 workers.
The Paroa Hotel is owned by Bernie Monk, whose son Michael died in the mine. Monk said a crowd of more than 100 gathered to hear the NZ First leader.
"He was overwhelmingly applauded by the people here today ... he is the first politician who has really stood beside us and made his feelings known."
Monk said his understanding of what Peters meant by "bottom line" was NZ First would not go into a coalition with any party that wouldn't commit to re-entry of the mine drift.
"He has always said ... that if a coalition happened, he would not go into coalition with any party that didn't support the Pike River families.
"Whether people around the country realise it or not, this is becoming an election issue - it is one of the issues on the table. And I think other parties are starting to follow Winston's lead - the Green Party has seven representatives coming down to the picket line on Wednesday."
English said he did not want to get into a debate about post-election coalition talks on the matter.
"What I am concerned about is that the families get some satisfaction out of this whole process which has been a real tragedy for them. They've had now years of distress out of it and it would be good if we could get to some kind of position where they feel they've had a fair go."
Peters would not confirm to the Herald that he wouldn't help form a Government without a commitment to a mine re-entry.
"We don't need translations about how the English language works ... a bottom line is a bottom line.
"Joe Bloggs down here in the West Coast knows what the bottom line means. Bernie didn't get it wrong, so why would you?"
Prime Minister Bill English has said the safety reforms that followed a Royal Commission into the 2010 disaster meant there were strict legal requirements about painting a one-storey house, let alone entering a potentially volatile mine.
Pike River was the "most dangerous workplace in New Zealand", he said, and approving a re-entry would go against the very health and safety laws passed by Parliament in response to the disaster.