Australia-based Bathurst, which is also listed on the New Zealand Stock Exchange, proposed to build the coal mine in New Zealand’s Denniston Plateau in 2011 and has been at the centre of a legal battle since.

An appeal on 12 points of law was lodged by the Royal Forest and Bird Protection Society of New Zealand on the Environment Court’s interim decision indicating it would likely grant resource consent for Bathurst’s Escarpment project.

The appeal relates to whether mitigation considerations relating to adverse effects on the environment are enough to be considered a biodiversity offset.

Forest and Bird withdrew seven points of law from the appeal, with three of the remaining five dismissed in their entirety by High Court Justice John Fogarty on Friday.

Fogarty flagged the remaining two points as minor issues that should be taken on board by the Environment Court when it decides on final approval for Escarpment on Wednesday.

Forest and Bird argued that some of the environmental work packages put forward by Bathurst were incorrectly viewed by the Environment Court as mitigating damage and the society wanted them reviewed.

Fogarty agreed and expressed the importance of the Environment Court distinguishing between “mitigation” and “offsets”

He expressed that mitigation related to the direct effects of mining activities whereas offsets related expressly to Bathurst’s proposed environmental package.

An appeal was also lodged against the preliminary decision of the Environment Court on the relevance of the adjacent Solid Energy Sullivan permit and was dismissed on Thursday.

Bathurst managing director Hamish Bohannan said the company was delighted with the decisions which brought it closer to the development of the project.

“We are pleased with the result and appreciate the guidance provided by the High Court,” Bohannan said in a statement on Friday.

“The matters raised by the High Court can be fully addressed in the Environment Court during the one-day hearing.”

But Forest and Bird believes it can still prevent the mine from being developed.

“This decision means the Environment Court will have to re-evaluate several points in our case to save Denniston from being open-cast mined,” Forest and Bird spokeswoman Debs Martin said.

“The Environment Court judge has already said that the case is ‘finely balanced’ so we’re hopeful today’s decision will cause the balance of his decision to shift in favour of protecting Denniston Plateau’s unique landscape, plants and animals.”