The federal opposition has challenged Environment Minister Tanya Plibersek to reveal her reasons for stalling the development of a $1 billion gold mine in the NSW Central West.
In August, the Commonwealth granted an Aboriginal protection order over the site earmarked for a tailings dam at the McPhillamys Gold Mine development near Blayney.
Regis Resources said that decision would make the project "not viable," in its current form, saying the process involved in finding an alternative dam site could cause a decade-long delay.
Nationals leader David Littleproud today called for more details to be released.
"We're saying to the minister, 'Give us the statement of reason'," he said.
"If you give us the statement of reason as to why you have actually rejected this application, then there will be a deeper understanding of the reason why.
"As far as the process that has been made publicly aware ... this company has ticked every box, and we will approve the mine if we are elected — we will get on and approve the mine, it is as simple as that."
The leader of the Nationals David Littleproud speaking at a press conference in Blayney. (ABC Central West: Toby Hemmings)
Mr Littleproud said the decision had ruined confidence in the planning process.
"The company was directed during their application to make negotiations … that is the process that takes place so that there can be investment confidence," he said.
"You have a set process that you can have confidence in that at the end of it, if you have met all those requirements … you should be able to get on your merry way."
The Belubula River originates at the mine site and its springs and tributaries bear significance and meaning for Wiradjuri people. (ABC Central West)
Regis Resources was required to consult with the Orange Local Aboriginal Land Council (OLALC) as part of its development application.
It initially opposed the project, but later changed its stance to neutral.
However, a Section-10 application to protect part of the Belubula River on heritage grounds was lodged by the Wiradyrui Traditional Owners Central West Aboriginal Corporation (WTOCWAC).
The former Coalition government upheld a Section-10 application lodged by the same group when it rejected a proposal for a Go-Kart track at the nearby Mount-Panorama-Wahluu.
Mr Littleproud said the circumstances surrounding the two decision were not the same.
"They're two different locations, two different traditional sites," he said.
"The local land council are the ones that represent local Indigenous people in that community, and they're the ones that are recognised."
Next week the Federal Parliament will hear a disallowance motion, brought on by Shadow Minister Jonathan Duniam, to overturn Ms Plibersek's decision.
The minister has rejected suggestions that her decision will result in lengthy delays, pointing to a recent surge in the company's share price.
Since Ms Plibersek made the decision, the stock price for Regis Resources has risen by 20 cents a share to $1.76.