Pike River victims' families say the Government's commitment to leave the coal mine unsealed and inspect it with drone technology falls short of their requests, but is still "very positive".
Prime Minister Bill English agreed today to put a halt to permanent sealing of the mine on the South Island's West Coast following talks with the families at Parliament.
English refused to grant their request to re-enter the mine's drift but agreed to look into sending a drone or other unmanned technology into the mine to investigate further.
The families' spokesman Bernie Monk said the meeting at the Beehive was "very positive" and that they had made more progress with English than they had under previous Prime Minister John Key.
"We've got another step forward for us ... I think they've got a lot of understanding about the ins and outs because it's not easy for them to understand what we've been through over the last six years."
But Anna Osborne, who lost her husband Milton in the 2010 incident, said English could have gone further. She described his commitments as "baby steps".
"He's not committed to giving the families any real reassurance," she said.
The families had hoped to convince the Government to allow a team to re-enter the mine or launch a new inquiry to check whether re-entry would be safe.
Following the meeting, English said the Government was bound by health and safety laws.
"This decision is not about politics, it is about safety. We lost 29 lives in that mine and I will not risk losing any more."
English said the families' proposal for re-entering the mine - which was written by two international mining experts and published in December - was not a detailed plan "and therefore does not make the case for a safe re-entry".
"Any decision to re-enter would also have to be made in accordance with our current workplace safety law, so the new directors would still have to take responsibility without indemnity for all aspects of safely entering the mine," he said.
"It's highly unlikely a new set of directors would decide it could be done safely."
English said he will request that Solid Energy halts work on the mine's permanent seal and "explore options for unmanned entry".
Robots had been tried at the mine in the past but had failed, he said. But the Government had recently been approached by experts with proposals for unmanned access.
The Government's former chief mines inspector Tony Forster, who is backing the victims' families in their bid for re-entry, said drone technology had advanced at "a significant pace" in the last few years.
"If will never completely satisfy the families in terms of physical re-entry, but if it's a step in the right direction and it gives us more information and narrows the angle in terms of the risks of re-entry, that can only be a positive."
English said it was not known how long the consideration of unmanned entry would take. He accepted that the issue could boil away during the election campaign.
Labour and New Zealand First have committed to re-entering the mine if in power.
Monk said the families would be removing a blockade on the access road to the mine after the Government's commitment not to seal off the entrance. The victims' supporters have blocked the road for 13 weeks to prevent Solid Energy contractors from reaching the site.
The mine has not been operating since a gas explosion in 2010 killed 29 workers, whose remains have never been removed because of concerns about high methane levels.