The Government is still working to differentiate between conservation and stewardship land which is why new mining activities have been approved across more than 150,000 hectares of public conservation land since 2017.
Official Information Act documents obtained by Forest & Bird have revealed that included in the approved mining activities was drilling for coal on the sandstone erosion pavements of the West Coast's Denniston Plateau.
The permits were approved despite the Government announcing in a speech from the throne in November 2017 that there would be no new mines on conservation land. A discussion document is still being prepared as the basis of public consultation.
Prime Minister Jacinda Ardern was asked on Thursday why the Government has continued approving mining on conservation land since 2017, despite promising it wouldn't happen when she took office.
"One of the things we have been working through, and has taken a little bit of time to work through, has been the difference between conservation and stewardship land," Ardern said.
"We have large amounts of land that are technically under stewardship land where these applications often apply and that's been one of the things as a Government we've been trying to resolve."
Stewardship land makes up about a third of Department of Conservation land and is a kind of holding pen for conservation land that is yet to be assessed for its values. It is not as highly protected as conservation land.
Energy and Resources Minister Megan Woods said until that work is resolved, the current policy settings stand, and that's why under the current settings some of those applications have been approved.
"We've already got in the works the tranche two changes to the Crown Minerals Act which is the legislation that governs that," she said. "We made the first stage of reform to that Act to bring about the end of the issuing of new exploration permits for oil and gas."
Dr Woods said the Government would have worked through the changes had it not been for the COVID-19 disruption.
Forest & Bird chief executive Kevin Hague said the Government made the promise to stop new mines on public conservation land, but has continued to approve prospecting and exploration activities in rare and precious areas.
"Allowing mineral exploration in these landscapes sends a strong signal that protected areas which are home to native species today will be mine pits tomorrow," Hague said.
"The majority of our conservation land is not currently safe from damaging mining activities - that includes ecological areas, scenic reserves, forest parks, and stewardship land.
"Despite being derided by some as being a 'wasteland', stewardship land is no such thing - it has simply not yet been formally categorised. These areas often have the highest biodiversity values of any conservation land."
It comes as Labour released its energy policy on Thursday ahead of the election, which includes bringing forward the 100 percent renewable electricity target by five years to 2030.
It also plans to investigate pumped hydro storage and green hydrogen, re-introduce the ban on new thermal electricity plants, introduce fuel efficiency standards for cars and support private sector decarbonisation.
Green Party co-leader James Shaw said Labour's energy policy is a step in the right direction, but the Greens would go further and faster to meaningfully tackle climate change.
The Government banned offshore oil and gas exploration in 2018, which National Party leader Judith Collins said on Thursday was a mistake because coal use has shot up in the absence of gas.
The Government's latest Energy in New Zealand report, which included information up to the end of 2019, showed 62 percent more coal was burned to generate electricity in 2019 compared to the year before.
Newshub revealed in June 2019 that the Government granted a coal exploration permit to BT Mining Ltd in September 2018, and Ardern admitted "how fragile sometimes our natural gas reserves" can be.