The group claims the partial approval decision by former federal environment minister Tony Burke in February contravened the Federal Environment Protection and Biodiversity Conservation Act of 1999.

Spokesman for the environmental group, Phil Spark, is quoted in the Australian Financial Review as saying the group will be calling on the Federal court to overturn the decision as the approvals were made in “haste”

“We are challenging the approval process of the Maules Creek and Boggabri coal mines because of the dodgy process by which they were approved and the devastating impacts they will have,” he reportedly said.

Earlier this month at the 11th hour, Burke moved out of the environment portfolio and was replaced by Mark Butler, who gave Maules Creek the green light.

The controversial project, which has drawn concerted environmental protests – including a hoax ANZ press release stating that a loan for the project had been withdrawn – is not in the clear yet.

Throughout the Maules Creek three-year approval phase, Whitehaven’s project development team tried to build a comprehensive project delivery strategy, which was finally validated by all levels of government, managing director Paul Flynn said.

“The project has been through one of the most rigorous planning approvals processes ever undertaken by a mine in New South Wales and has been reviewed by a wide range of highly regarded environmental experts,” he said.

“The project is one of the most significant investments currently underway in regional NSW.

“We will be commencing construction imminently now that contracts can be executed.”

There are growing fears that protesters will resort to legal means to derail more NSW coal project approvals, as they did against Rio Tinto’s proposed Warkworth Complex extension in the NSW Land and Environment Court.

The uncertainty around the planning approvals process and the threats to legal challenges in NSW was raised by Rio Tinto Energy’s chief executive Harry Kenyon-Slaney in a recent speech. He called on the government to create more certainty in the process.

“A current example in my business is a New South Wales court decision this year which overturned consent for an extension at one of our Hunter Valley mines,” he said.

“It is a 30-year-old mine. The consent was approved by state and federal governments during a rigorous three-and-a-half year public process. This court decision has now created uncertainty for every major new investment project planned in that state, as well as for existing mines simply requiring approval to continue operating.

“Uncertainty is a threat to the broader economic development of NSW and I’m calling on NSW Planning Minister Brad Hazzard to restore clarity and certainty to the planning system in his state.”