Queensland Aboriginal activist Murrandoo Yanner has joined traditional landowners in the Northern Territory to stop mining giant Xstrata from expanding its operations.
The courts have cleared the way for the miner to increase the size of its McArthur River operations near Borroloola, to extract rich zinc deposits under the river.
Traditional owners say plans by the company to divert six kilometres of river are shocking and unacceptable.
Mr Yanner says if Xstrata attempts to change the course of the river the dispute will escalate.
"This is going to be an ongoing mother of all battles between the traditional owners of Borroloola and multinational Xstrata," he said.
"This protest ain't going to go away, it is going to be ongoing in the coming days, weeks, months, and if need be years.
"If I was an investor in Xstrata I would be withdrawing my money and investing elsewhere, because the shares are about to devaluate."
Mr Yanner has urged Prime Minister Kevin Rudd to intervene before the dispute escalates.
"Kevin Rudd is talking all the talk about the environment - well how does poisoning a river and re-diverting a whole river after we've seen what happens to the Murray [sound]?" he said.
"Kevin Rudd needs to talk the talk and walk the walk - McArthur River Kev, put up or shut up."