An open-cast coal mine is a step closer to going ahead after being given the green light by the West Coast Regional Council and Buller District Council.

The Te Kuha mine will cover 144ha, with 12ha on conservation estate and 100ha on the Westport Water Conservation Reserve, while the remainder is on private land.

But the approval of the mine is being challenged by the Coal Action Network Aotearoa (CANA), who say this will test the new Labour Government and their stance on conservation policy.

CANA says the coal mining company will remove the mountaintop in a West Coast conservation park if the mine goes ahead.

"Earlier this month Conservation Minister Eugenie Sage signalled there would be no new mines on conservation land," says CANA spokeswoman Rosemary Penwarden.

"This is now her test - will (Ms Sage) allow a coal miner to take the top off a mountain, in an area that contains the endangered great spotted kiwi," Ms Penwarden said.

Meanwhile, the Department of Conservation is yet to make a decision on an access arrangement, or the use of the water reserve.

Buller District Council Mayor Garry Howard told NZ Newswire, that the access arrangement has been a long time coming, and he understands it was agreed to by the prior government, therefore making the transition with the new government "interesting".

Mr Howard said while New Zealand's environment needs to be respected in the process, the country has to understand that they cannot turn their backs on coal mining either.

"We need to transition and have mining as part of the mix in our economy," he said.