Greenpeace is warning the Government it could face civil disobedience and an international backlash if it proceeds with mining on conservation land.

As part of his State of the Nation address, John Key announced plans to amend schedule 4 of the Crown Minerals Act to allow mining on New Zealand's most important publicly owned conservation lands.

"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.

"Frankly, if I was a mining company I'd be looking to invest elsewhere.

"This issue is something New Zealanders feel very strongly about; John Key acknowledged as much in his speech. The Government holds our National Parks in trust for all New Zealanders.

"But the backlash won't just come from within New Zealand. This announcement will come as a huge disappointment to anyone who's ever travelled here from overseas and enjoyed our land and scenery. And any international backlash will affect our tourism and agriculture sectors."

"There's already international concern about the Government's plans. Does John Key really want the reputation of being the George Bush of the South Pacific?"