Greens MP Cate Faehrmann called for laws preventing the clearing of high-conservation value land in NSW as federal Environment Minister Tony Burke prepared to announce his decision on whether Maules Creek gets the green light.

"The report found that by far the greatest pressure on threatened species is land clearing, yet the government is under pressure to wind back land clearing laws on private land in rural areas,” he said.

"Mining in areas of high conservation value is under full swing in NSW, with Whitehaven's proposed coal mine in the already heavily cleared Liverpool Plains set to clear 2000 hectares of high-quality forest alone.”

The state government has sent strong signals that it's going to weaken laws designed to protect threatened species, Faehrmann said.

“What is urgently needed is a serious regulatory approach from the government that will halt the decline in the state's biodiversity, not exacerbate it,” she said.

"It's unacceptable that a further 35 native plants and animals in NSW have been listed as threatened since 2009.”

Farmers whose properties might be impacted by the proposed open-cut coal mine in Leard Forest near Boggabri arrived in Sydney yesterday to release an ecologist’s report they said highlighted discrepancies in Whitehaven Coal’s biodiversity offsets program, a critical element of the company’s application.

Nature Conservation Council chief executive officer Pepe Clarke said Whitehaven Coal planned to clear more than 500 hectares of critically endangered white box-gum woodland, which required offsets of the same ecosystem type to be protected elsewhere.

“However, the areas that the company has mapped as endangered white box-gum woodland in their proposed offsets are in fact a totally different vegetation type,” Clarke said.

“The vegetation in the offsets is not endangered, contains little or no white box and does not provide habitat for the threatened species the offset was supposed to protect: the swift parrot, regent honeyeater or corben's long-eared Bat.

“The NSW government has approved the mine on the basis of the highly questionable offsets and a final decision on whether the mine will be approved by the federal government is now imminent.

“The federal government must reject the proposal and investigate whether the company has provided false or misleading information to obtain an approval under federal environment law.”

Managing director Tony Haggarty told ILN that Whitehaven had worked in consultation with state and federal departments, as well as highly regarded independent ecology experts, in relation to the ecological studies involved on the Maules Creek mine site and the offset sites that have been put in place.

“Any suggestion that these studies have not been conducted and presented in a transparent and professional manner is highly misleading and deceptive,” he said.