A quiet change to Shenhua’s New South Wales planning conditions for its open-cut Watermark coalmine could desecrate sites of Indigenous cultural significance before the federal environment minister decides whether they should be protected.

Gamilaraay man and native title applicant for the Gomeroi people, Raymond Weatherall, has warned successive failures to protect sacred places on the development site in the Liverpool Plains in north-west NSW, could lead to direct conflict between the Gomeroi, the state government and the Chinese state-owned company Shenhua.

He is one of the approximately 190 Gomeroi applying to the federal government for permanent protection of their sacred sites under the Aboriginal and Torres Strait Island Heritage Protection Act (ATSIHP) with the support of the NSW Aboriginal Land Council.

Just before Christmas last year, the NSW planning department approved Shenhua’s request to change the consent conditions, allowing “pre-construction works” to start on the site, even though a mining lease has yet to be granted.

The NSW “modification”, signed off by a senior bureaucrat David Kitto under delegation from the minister, changed the usual definition of “commencement” to allow pre-construction works to include “geotechnical drilling or excavation, minor clearing and minor access roads”.

While the proposal has received development consent from the NSW Coalition government and conditional approval from the then federal environment minister Greg Hunt, two crucial management plans on water and biodiversity are required under the “water trigger” laws before the mine can go ahead.

Prior to the NSW change, Shenhua could not start these pre-construction activities without meeting these conditions.

Native title applicant for the Gomeroi people, Raymond Weatherall: ‘We are effectively denied access and rights on lands and waters which are our custodial rights.’

Gomeroi applicants, including Weatherall, are concerned the latest change in process denied the local Indigenous people any rights to seek protection and “have a voice”.

“We are effectively denied access and rights on lands and waters which are our custodial rights and lands we have never ceded, never sold and never gifted,” he said.

“The NSW government are very well aware of our ATSIHP application and protracted battle to protect and defend our sacred places yet these appear to be deliberately ignored and legislation and processes developed which in effect sidestep or excuse the government from taking protection action.

“The systemic and successive failures will only lead to direct conflict between the Gomeroi and a foreign government-owned mining company Shenhua and the state government who claim to be elected for all people.”

But a spokesman for the NSW planning department said the conditions of consent require Shenhua to prepare a heritage management plan prior to the commencement of construction.

“This plan must include a description of the measures that would be implemented to protect and manage Indigenous heritage items on the site,” he said.

“Construction of the mine may not commence until this plan has been approved by the [planning] secretary.”

Liverpool Plains in north-west New South Wales. Photograph: Jeremy Buckingham

After Hunt granted Shenhua conditional approval in 2015, the minister promised that he would go further than any other minister in history before giving the final approval to the Shenhua mine.

The Gomeroi’s 2015 application to Hunt sought both emergency and permanent declarations to protect a number of important areas, including Mount Watermark, two grinding grooves areas and a sacred men’s site.

A federal department of environment briefing to the minister, seen by Guardian Australia, acknowledged there was sufficient information to be satisfied that Gomeroi areas were “under serious threat of injury or desecration”.

However the federal department argued to the minister that the sites were not under “immediate threat” because media reports in February 2016 indicated Shenhua Watermark had not applied for a mining lease.

Hunt wrote to the Gomeroi applicants that he was unable to make an emergency declaration but that, in continuing to consider their application for permanent protection, he appointed barrister Susan Phillips to investigate.

“Shenhua must obtain my approval of a biodiversity management plan and a water impact verification report before mining can commence,” Hunt wrote. “Shenhua has not yet submitted the plan or report for approval. Therefore I am not satisfied the area is under immediate threat of injury or desecration.”

More than two years later, the water and biodiversity reports required by the federal government have still not been submitted, but Shenhua has been given the green light by the NSW government to start pre-construction works.

There has been two subsequent federal environment ministers, Josh Frydenberg and the current minister Melissa Price, but the Gomeroi applicants are still awaiting the outcome of a determination of the permanent protection application, based on a report by Phillips.

Price said the Phillips report would not be released publicly due to culturally sensitive and legally privileged information, but would make the decisions “as expeditiously as practicable”.

“The changes to the state approval do not affect the federal approval conditions as the requirements set out in these conditions are linked to project milestones rather than specific dates,” Price said.

Gomeroi native title applicant Steven Talbott with traditional custodians spokesperson Dolly Talbott.

“Construction of the mine cannot commence without my approval of this plan.”

Prior to the mine proposal, the Gomeroi had access to their sites via the former landowners, but since the proposal, they have only been allowed to access land wholly owned or leased by Shenhua while accompanied by Phillips and Watermark mine representatives.

Gomeroi traditional custodians spokesperson Dolly Talbott and native title applicant for Gomeroi people, Steven Talbott, said while a 2017 visit with Phillips was appreciated, they had been largely denied access.

“We simply do not understand how a state government or federal government can provide such levels of power and rights to a foreign company to the detriment of the First Peoples of this country when the high court ruled that Terra nullius was a lie and under the commonwealth’s own legislation were found to be wrong,” Dolly Talbott said.

Farmer Susan Lyle of the Caroona Coal Action Group said building the mine on the Gomeroi sites was tantamount to building a housing development on Rookwood cemetery.

“I believe when the [then] federal environment minister Josh Frydenberg had knowledge of the burial sites, he should have stopped the development immediately,” Lyle said.

Shenhua has applied to extract 268m tonnes of coal from the Watermark open-cut mine 25km south-east of Gunnedah, surrounded by some of Australia’s most productive agricultural land.

Fierce opposition from sections of the farming and Indigenous communities began when the Chinese state-owned company was granted an exploration licence for $300m by disgraced former NSW Labor resources minister Ian Macdonald in 2008. Since then, the Berejiklian government bought back 51% of the licence from Shenhua and paid the company a refund of $262m in 2017.

Lock the Gate Alliance lost an appeal to the NSW Civil and Administrative Tribunal to access the buyback documents because they involved confidential negotiations, even though it acknowledged there was “a good deal of public interest” in the decision which involved “significant sums of public money”.

A spokesman for Shenhua, Gerry McDonald, said the NSW modification was required to fix some dates in the development approval that were “clearly meaningless” and to clarify whether soil testing would trigger various obligations. He said the company remained fully committed to the mine going ahead.

Of the Gomeroi, McDonald said the claim was yet to be determined and the claimants were a small group.

“The reality is that the group making the claim are only a very small group where the majority of the local Indigenous Gomeroi people around the area do support the project primarily because they want to see job opportunities for their families,” McDonald said.

“Second, the soil testing will not destroy any of the areas or artefacts and have been specifically designed to avoid such areas and artefacts.”

Dolly Talbott said claims they represented a small group was part of the “normal shit” the company did. She said under law, only one applicant was needed for an ATSIHP application and the Gomeroi application had 190 people, the support of the NSW Land Council and they represented 15,000 Gomeroi people.

“Why are they trying to diminish our voice and being so racist and disrespectful?” Talbott said.

“I’ve just about had gutful. Even if the application is not successful, it’s not over. It will only keep ramping up. If the government or Shenhua think we are going to roll over, they have another thing coming.”