The Green Party is worried a precedent is being set by granting a mining permit for some protected Schedule Four conservation land, but the Government says it is scaremongering.
A permit for an area including three hectares of Coromandel Forest Park has been granted to the Broken Hills Mining Company, which operates a small gold and silver mine near Whangamata.
The office of Energy and Resources Minister Simon Bridges says the mining company plans to build a second exit on the land in order to comply with safety regulations brought in after the Pike River disaster.
It says the conditions of the permit don't allow mineral extraction.
Green Party mining spokesperson Catherine Delahunty says she wants to know why the mining company needs three hectares of land to build a small escape shaft.
Ms Delahunty is also worried other mining companies will use the case as a precedent to expand their operations into conservation land.