Mr Baird this week pledged his support for what he emphasised was an independent assessment of the $800 million project.

Opponents of the coal mine have been calling for Mr Baird to honour a promise from former premier Barry O'Farrell to stop the mine.

But Mr Baird wasn't budging when he told ABC Central Coast radio: "There is a process under way, and it is independent, and that's important," he said of the Planning Assessment Commission's work.

"This is an independent process carried out by experts, and that's the way it should be."

The controversial coal mine saga entered a new phase late last year with the state government directing the mining company and Darkinjung Aboriginal Lake Council to enter mediation to resolve a stalemate.

At issue is a Land and Environment Court ruling that Kores Australia's development application for the mine could not be determined until the NSW Aboriginal Land Council has given its consent for the Korean-owned company to use Darkinjung land for a rail spur to access the mine west of Wyong.

Darkinjung opposes the mine and has demanded $300 million for access to the land.

The mining company described the asking price as "extortion".

The government has written to both parties advising that it would facilitate the mediation.

Darkinjung chief executive Sean Gordon said he'd prefer the state government to put the matter to bed before the election.

"They should be just coming out and knocking the mine on the head, but they won't," he said.

A spokesman said Kores Australia was "continuing the commercial negotiations in good faith".