The proposal to expand Centennial Coal’s Springvale mine’s underground coal mining area allowing it to operate for another 13 years has been referred to NSW independent Planning Assessment Commission for a final decision.

But the fate of 300 workers at the mine who have been stood down since August 21 is still unknown because the extension project still needs federal government approval.

Construction Forestry Mining and Energy Union south western district vice president Graeme Osborne said the company had been seeking an extension of the mine since 2012 but because of the NSW Government’s "confusing and convoluted" planning process they were still waiting.

“Mineworkers, their families and the Lithgow community have been left in the lurch for far too long as the NSW Government panders to green groups at the expense of workers,” he said.

“The Springvale coalmine has been a part of the Lithgow community for more than 20 years and directly employs almost four hundred local workers.

“We are already starting to see the very real effects of this irresponsible behaviour. The first stand downs of Springvale mineworkers took place on Friday evening and many more workers will be stood down in the coming weeks.

“We’re calling on the local Nationals representative Paul O’Toole to stand up for local workers instead of standing by and allowing Planning Minister Rob Stokes to play politics with our jobs and the future of our community.

“Without the mine’s approval, many hundreds more local mineworkers will be out of work by the end of September when Centennial Coal will be forced to stop production and place the mine into care and maintenance.”

Osborne said the Springvale mine is the sole provider of coal to the Lithgow Mount Piper Power station and if the mine extension is not approved it is likely the power station will also be forced to close, taking hundreds more local jobs with it.

“In the Lithgow area 20 per cent of all jobs are tied to coal mining and power generation. Our region has already been hit hard by hundreds of job losses when the Wallerawang power station closed and Centennial’s Angus Place coalmine was placed into care and maintenance last year.

“Unemployment in the Lithgow area is now almost 10 per cent – a rate well above the regional NSW average.

“If this approval is not granted it will have a devastating impact on our tight-knit community in Lithgow.”

Centennial Coal executive general manager external affairs Katie Brassil said the company has no option other than to stand down the majority of the Springvale workforce because of the delays in approval.

As of Friday last week the majority of the Springvale workforce have now been stood down.

Centennial Coal executive general manager external affairs Katie Brassil said: "There was huge community support for the rally on Saturday with close to 1000 people turning out to support our Springvale workforce.

"Our people at Springvale mine and the entire Lithgow community are being significantly impacted because Minister Stokes failed to consider the 'unintended consequences’ to existing mining project like ours when he proposed changes to the Mining SEPP (Clause 12AA resource significance).

"Springvale has been operating for over 20 years and is seeking to renew its consent to continue operating for a further 13 years.

"We started this consent renewal process in September 2012 (three years ago next month) and a change proposed by the Minister in July 2015 (at the 11th hour) is going to prolong the state's assessment process by sending, our time critical project, to a second Planning and Assessment Commission including a second Public Hearing.

"Due to the delays in being unable to secure the appropriate approvals the majority of our Springvale workforce (in excess of 300 employees) have been stood down since Friday August 21. We are collateral damage for a government who has a history of changing the goal posts without considering the consequences.

"Mr Stokes needs to 'own' his and his government’s actions and apologise to our people at Springvale and the Lithgow community."

The application has been put under the microscope through a number of extensive reviews, involving analysis by independent experts and community consultation, a NSW Department of Planning and Environment spokesperson said.