Revelations that more conservation land will be mined, whatever the outcome of public consultation, have drawn vehement opposition from environmental groups, who say conservation land is about to be destroyed.

The Government is planning to consult the public over opening up more land for mining, but Prime Minister John Key signalled to Parliament yesterday that there would be significant changes to which areas are protected.

Schedule 4 of the Crown Minerals Act protects about a third of the conservation estate from mining because of its conservation value. That equates to 13 per cent of New Zealand's land mass.

It is expected that the Government will seek consultation this month on removing land in Coromandel and the Mt Aspiring, Kahurangi, Fiordland and Paparoa national parks from Schedule 4.

Green Party co-leader Russel Norman said it appeared Mr Key had already decided the outcome of the public consultation process, before the public had been given an opportunity to see what was being considered.

"Clearly he is proposing an unlawful process."

The result would be that some of the most important ecological land would be destroyed, causing irreparable damage to New Zealand's green image and tourism industry.

In his speech, Mr Key said a conservation fund would be established through royalties from mining revenue, but Dr Norman pointed out that the plan was illogical. "We have to destroy the environment in order to protect it."

Forest and Bird Advocacy manager Kevin Hackwell said the conservation fund was "public relations fluff". Any mining company should already be doing everything it could to repair any damage it did to land.

Although Mr Key had previously said modern "surgical" mining techniques meant that mining operations no longer had to have a major environmental impact, Mr Hackwell rejected this.

"It's a chainsaw massacre. The days of making a small hole are long gone. Mining is about huge, huge holes in the ground."

Land protected under Schedule 4 cannot currently be used for opencast mining, but Mr Hackwell said once this changed, conservation land would be left with massive scars where mountains and hilltops had been removed to get at coal.

North Island land at risk through changes to Schedule 4 included parts of the Coromandel Peninsula containing gold deposits and heavy metals, and the West Coast of the North Island between Raglan and New Plymouth containing ironsand.

In the South Island, copper and zinc deposits were thought to exist under Kahurangi National Park, while the West side of the Paparoa National Park contained coal.

Other areas in the West Coast had gold deposits and heavy metals.

Further south, the Waitutu forest in Fiordland was thought to contain gold and gas deposits.

Greenpeace political adviser Geoff Keey said Mr Key's announcements could generate a "civil disobedience" backlash from activists, and would adversely affect tourism.

Tourism Industry Association chief executive Tim Cossar said he was reassured by Mr Key's comments that any new mines would have to meet strict environmental tests, but was watching the issue closely.

Minerals Industry Association chief executive Doug Gordon supported the establishment of a conservation fund.

"When we're talking about mining minerals from the mineral estate which is below the conservation estate it makes sense."

He said there was "no way" the minerals industry wanted to lose the trust of New Zealanders, but it would be beneficial to be able to access more areas for exploration.