The Barwon MP met with Whitehaven executives and advised them to come to a compromise, rather than going ahead with its current proposal, which would more than double the mine’s output.

“If they push ahead with an all or nothing proposal, they are going to meet some strong resistance – from both the locals and from myself,” Mr Humphries told The Leader.

Mr Humphries said the extension would exacerbate the “boom and bust” cycle many mining regions go through, as “increased production often leads to less employment overall”.

“We’ve been able to manage the boom and bust mining cycle better than most other places because we maintain steady growth,” he said.

“Large scales mines, just like large scale agriculture, are now based on systems and technology that over time achieves much higher production levels with fewer people employed.”

At its current rate of extraction, 4.5 million tonnes of coal a year, the mine has an estimated lifetime of more than 40 years.

If its production was upped to the proposed 10 million tonnes a year, the mine is expected to last 15 to 20 years.

Mr Humphries also has major concerns about the mine extension’s proximity to the nearby Namoi River.

Project plans show it would come within 500 metres of the river’s banks.

Mr Humphries said he wasn’t anti-mining and previously supported the initial Whitehaven approval, which saw the Vickery mine extended to its current size.

A Whitehaven Coal spokesman said the project’s Environmental Impact Statement (EIS) would thoroughly deal with all potential environmental and other impacts associated with the proposed mine.

“The EIS includes a significant stakeholder and community engagement component, so everyone will have an opportunity to have their say on the project,” the spokesman said.

“Whitehaven will address any issues and concerns that arise in this context.

“The EIS will be lodged in the current half, at which point we will have more to say about Vickery, including the substantial economic and employment benefits it will deliver to communities in the North West.”