The Green Party is vowing to "stop the bulldozers" and environmental groups are outraged over the Government's decision to allow mining on conservation land.
Prime Minister John Key told Parliament yesterday that removing protection from some areas was being considered, although there would be a public consultation process.
He said he expected there would be "significant changes" to schedule four of the Crown Minerals Act, which protects designated areas from mining.
"This is because new mining on Crown land has the potential to increase economic growth and create jobs," he said.
Schedule four of the Crown Minerals Act protects designated areas from mining. A stocktake of valuable minerals in land covered by the schedule was undertaken last year and the untapped value has been put at about $140 billion.
Mr Key said there would be a new Conservation Fund established, which would receive some of the revenue from mining operations.
It would be used to fund conservation projects.
Green Party co-leader Russel Norman said there would be a groundswell of opposition to mining conservation land and the Greens would be there to fight any attempts to do it.
The party's other co-leader, Metiria Turei, told NZPA it was a terrible decision.
"He's going to cause enormous damage to our tourism industry, he's going to radically affect our biodiversity values in this country which are already at serious risk," she said.
"He's going to try to sell off the conservation land to international mining interests and expect that the country will be satisfied with a small conservation fund."
Greenpeace said the Government could face serious problems.
"If National opens more conservation land for mining, and particularly national parks, it is highly likely to face civil disobedience of the sort that saved West Coast forests and Lake Manapouri," said Greenpeace's political adviser Geoff Keey.
"This issue is something New Zealanders feel very strongly about. The Government holds our national parks in trust for all New Zealanders."
Mr Key also predicted an international backlash that would affect tourism.
"This announcement will come as a huge disappointment to anyone who has travelled here from overseas and enjoyed our land and scenery," he said.