Forest and Bird says the Government should not be getting money for conservation from an Australian mining company.
The Government has given Bathurst Resources access to conservation land on the South Island's West Coast.
Conservation Minister Nick Smith on Thursday approved its application for an open-cast coal mine on 106 hectares of Denniston Plateau's 2026 hectares near Westport.
The land involved is not part of a national park or conservation park, but is general stewardship land controlled by the Department of Conservation (DoC).
The mining company will pay for a $22 million package to fund pest and predator control in the Kahurangi National Park as well as on or around the Denniston Plateau.
However, Forest and Bird advocacy manager Kevin Hackwell says the work Bathurst Resources is paying for is already being done by DoC.
Mr Hackwell said on Friday the Government should not be getting conservation funding from a mining company and questions whether it will pay enough.
"There shouldn't be a situation where the Government carries on underfunding DoC and can just say, 'Oh it's all right because we'll just hock another piece of land off, we'll allow mining to happen somewhere else and we'll be able to carry on underfunding the department.'"
Mr Hackwell said Bathurst Resources is in a boom and bust industry and there is no guarantee that the company will be in a safe financial position in a few years.
The Green Party says the Conservation Minister is ignoring public process by pushing through an agreement with Bathurst before changes to the Crown Minerals Act require public consultation come into effect on Friday.
Nick Smith said making the decision on Thursday meant that the Government got a better compensation package from the company.
However, Green MP Catherine Delahunty said the Government was always going to cut a deal with Bathurst under either law.
Many residents for mining
Many people on the West Coast say they are relieved and encouraged by the Government's decision to allow Bathurst Resources access to land on the Denniston Plateau.
The Bathurst consents granted in 2011 are being appealed against at the Christchurch High Court next week. The Environment Court has said that if the court rejects the appeals, it will sign off the consents in mid-June.
If the mine does go ahead, it would create 450 new jobs for the Buller region and could be operational by Christmas 2013.
Westport resident Kathleen Reynolds said companies are shutting up shop in Buller and the economic situation is near breaking point.
Ms Reynolds said people are walking away from their homes to look for work outside the region.
Another resident, Richard Fairbrows, said the mine would come just in time for Buller.