Environmentalists have flagged ramping up opposition to a contentious proposed waste dam at a mine in Tasmania after losing a legal challenge relating to the project.
Chinese-owned mining company MMG wants to build a new tailings dam at its operations near the town of Rosebery in the island state's west.
The Bob Brown Foundation applied for a review of a mining lease granted by the state government in 2022 covering an access road to the proposed dam site, arguing it was not legal and part of a strategy to exclude protesters.
The application was dismissed in the Supreme Court of Tasmania on Wednesday.
Former Greens leader Bob Brown lashed the decision as "appalling", saying his foundation would consider appealing to the full bench of the court.
"This decision will simply stir us to a bigger effort to protect the Tarkine (rainforest) from MMG's waste dump," he said outside court.
The final call on whether to approve the tailings dam is in the hands of federal Environment Minister Tanya Plibersek.
"What you can be sure of is, we'll be in those forests," foundation campaigner Scott Jordan said.
"There are people standing there today, we are defending those forests and we'll continue to show the world what's there."
The foundation argued the lease didn't need to be granted, as MMG already had the right to use the road.
In dismissing the legal challenge, Justice Alan Blow ruled it was open for then-state Resources Minister Guy Barnett to grant the lease, which gives MMG the power to upgrade the road and clear land.
Justice Blow said it was also open for Mr Barnett to conclude protest activity was likely to impact MMG's use of the road and to take that possibility into account when deciding whether to grant the lease.
"The minister's discretion to grant (the lease) was not fettered in any way by the legislation," Justice Blow wrote.
"Members of the public have a right to protest. However the minister was not obliged to prefer the interests of protesters to those of MMG."
State Resources Minister Felix Ellis said the court's ruling validated the lease.
He said the government was a strong supporter of MMG's project, noting it must comply with environmental and planning standards.
"It is disappointing, but not surprising, that the radical Bob Brown Foundation continues to oppose a proposal that would help secure 500 regional jobs," Mr Ellis said.
Preparatory work for the proposed tailings dam was put on hold last year following a decision by the Federal Court.
MMG has previously said it needs a new tailings dam for the mine to operate past 2024, and the proposed site is the company's preferred spot.
