'Disgraceful': Geoffrey Watson accuses Minns government of overturning high court ruling on coalmine

New South Wales government bid to expand Hunter Valley mine 'contrary to separation of powers', leading legal experts say

Barrister and anti-corruption campaigner Geoffrey Watson SC has lashed the New South Wales government over its "disgraceful" plan to adopt special laws allowing increased coal production at a Hunter Valley coalmine.

The high court ruled earlier this month the approval of the Mount Pleasant mine in Muswellbrook was invalid.

But the premier, Chris Minns, announced Monday the government would introduce a bill allowing MACH Energy to increase coal production at the mine by 32% to 16.5 million tonnes per year.

Minns said the legislation was necessary to save 400 jobs at the site before Christmas.

"I think it's disgraceful," said Watson, a director at the Centre for Public Integrity and former senior counsel assisting the NSW Independent Commission Against Corruption.

"This is, in effect, to overturn a decision of the high court of Australia after a fair hearing.

"In my book it's contrary to the separation of powers which acknowledges that each branch of government has its own area or domain."

Anthony Whealy, a former supreme court judge and another director at the centre, called the government's decision "generally reprehensible".

He said the centre had done considerable work examining the "dangers and perils" of unregulated lobbying by major companies, particularly the fossil fuel industry.

"I am concerned, and I think it is generally reprehensible that in this case, a major foreign company has clearly made representations to the Minns government," Whealy said.

"And the Minns government has, by deciding to put out this legislation, completely ignored the significant decisions by the New South Wales court of appeal and the high court."

Whealy said the government had also "disrupted and effectively obliterated the prospect that the issues surrounding this mining venture would have been resolved in the land environment court".

The October high court judgment found the Independent Planning Commission (IPC) failed to consider imposing conditions aimed at minimising emissions generated when the coal was burnt overseas - known as scope 3 emissions - to the greatest extent possible.

The next step in the proceedings was for the matter to return to the land and environment court for consideration.

Whealy told Guardian Australia: "All of that's been set aside by Minns acting in this way, I think, for political purposes."

"And it demonstrates the dangers of unregulated lobbying and the dangers of creating laws without public consultation."

On Wednesday morning the NSW Greens questioned the government's justification that the legislation was necessary because jobs were on the line at the mine.

They pointed to a job advertisement, posted by MACH conctractor Thiess on jobs site SEEK for multiple roles, hours after Minns' announcement on Monday.

"The government is being fed lies about the job numbers at Mount Pleasant, and they are lapping them up while selling the integrity of the NSW planning and legal systems down the river," Greens climate spokesperson Sue Higginson said.

It followed a heated debate in parliament on Tuesday, where the party raised concerns MACH Energy had increased the coal output of the mine while the matter was before the high court.

Correspondence between the NSW department of planning and Johnson Legal, which represented the Denman Aberdeen Muswellbrook Scone Healthy Environment Group (Dams Heg) in the court proceedings, shows the group had raised concerns MACH Energy may have commenced the expansion at Mount Pleasant after its approval was found invalid by the NSW court of appeal.

Later correspondence raised concerns the company was mining coal above its set production limits.

In a letter on 14 August, the planning department confirmed "an investigation has been commenced by the department into the operations of MACH Energy at Mount Pleasant".

The precise nature of the investigation was not specified and the department declined to provide further detail when asked by Guardian Australia.

Resources minister Courtney Houssos said any investigation "into the mine's compliance with its planning approvals is a matter for the regulator".

"Whether any breach has occurred is yet to be determined," she said.

She said the government's legislation "will not prevent that investigation or excuse any breaches of existing planning conditions". She said the company had told the government it obtained legal advice stating its 2022 planning consent remained valid during the High Court proceedings.

Houssos repeated this in question time on Tuesday afternoon, telling parliament the company "has increased its production because they have legal advice that says that they had approval to operate at the higher rate, and as a result, they took on additional workers".

Guardian Australia sought comment from MACH Energy.

In a statement on Monday, the company said it had "continually assured local communities that we would actively explore all options to protect this important project".

"MACH Energy obtained legal advice that confirmed the 2022 consent remained valid during the High Court proceedings," the statement said.

Further comment was sought from Minns.