There is not enough information available to decide on whether mining should be allowed in some currently protected areas, the Parliamentary Commissioner for the Environment Jan Wright says.
The Government last month released a discussion document proposing removing some conservation areas from Schedule 4 of the Crown Minerals Act, which protects them from mining.
Those areas include parts of Great Barrier Island, the Coromandel and Paparoa National Park.
In her submission on the Government's discussion document, Dr Wright said the Government had not made a case for opening up certain land to mining.
There was a lack of information available about the conservation value of the land, the benefit of mining it and problems raised by the joint access approval, she said.
"These areas have been set aside as some of our most precious conservation land and before we can even begin to discuss mining it in any rational manner, we need a lot of good information which simply hasn't been made available."
Dr Wright recommended none of the specified areas be removed from Schedule 4 due to insufficient information. She also recommended the ambiguity in the Crown Minerals Act be resolved to prevent land being automatically entering into Schedule 4 and to ensure the proper administration and use of a proposed conservation fund.
She said she was expecting to issue a full report on mining on conservation land by the middle of the year.
Energy and Resources Minister Gerry Brownlee said Dr Wright was an "interesting person".
"She's had a lot to say about a number of things that have been interesting recently. We obviously take into account the quality of that work as well...I would say thank you for the report I'll read it with some interest," he told reporters.
Dr Wright had proposed a catch-22 situation -- she has called for economic argument but that is prohibited because of Schedule 4, Mr Brownlee said.
"The only way we can find that out is by removing the Schedule 4 ban on exploration. You can go out there with a pick and shovel but you need to go and explore the thing before you know exactly what's there."
It was not possible to be accurate about the mineral content while the Schedule 4 protection remained, he said.
"The desktop analysis looks good here. New Zealanders do you think we should have a closer look?
"If it's her opinion that we shouldn't, well she should say so but she doesn't. She's put in front of us a circular argument that takes us nowhere."
Labour leader Phil Goff said the Government was more interested in what the mining lobby had to say than New Zealanders who wanted to protect conservation land.
"Dr Wright slams the quality of Mr Brownlee's work, saying that the 'issue is too important to rely on inadequate information'," he said.
Mr Goff described Dr Wright as "Parliament's environmental watch dog".
The Government's mining plans did not stack up environmentally or economically, he said.
"The consultation is a sham. Labour is opposed to mining in national parks and other Schedule 4 areas like the Coromandel."
Green Party co-leader Metiria Turei said there was a widening gap between Mr Brownlee's public statements and actions.
"The public continues to be misled," she said.
