A private member's bill to disallow an extension of the indenture for the planned Olympic Dam mine expansion has been defeated in the South Australian Parliament.
The bill was moved by the Greens but defeated by the Government and Opposition.
Greens leader Mark Parnell argued environmental standards would change over the four years of the extension and the indenture would need changes.
"They're proposing to come back with something different anyway and most of it will have to be re-negotiated, especially through the EIS (Environmental Impact Statement)," he said.
"The Government has said that there are a range of sweeteners if you like, benefits that BHP Billiton has promised in exchange for the extension.
"I'd like to know how many of them are locked in law the same way that the state's commitments to the company are locked in law effectively forever." The motion's defeat prompted an outburst from the visitors' gallery.
"[You are] all a bunch of scumbags working out of the corporate pocket," a heckler said.
BHP Billiton has committed to spending $540 million over the next four years re-designing the proposed mine expansion, but given no commitment on proceeding.
The indenture has been extended until late 2016, to give the company more time to investigate an alternative ore extraction method.
BHP is also hoping global market conditions will improve.