The Federal Court of Australia has thrown out two other bids to stop the controversial Adani coal mine going ahead in central Queensland.
The full bench dismissed appeals by the Australian Conservation Foundation and traditional land owner Adrian Burragubba on Friday.
The ACF had sought to successfully argue a legal technicality that Environment Minister Josh Frydenberg had not considered the effect of the mine's emissions on the Great Barrier Reef under the Environmental Protection and Biodiversity Act.
Mr Burragubba had appealed against a decision by the National Native Title Tribunal that allowed the Queensland government to issue a mining lease for the proposed Galilee Basin site.
ACF campaign director Paul Sinclair said the Federal Court's decision to dismiss its appeal showed Australia's environmental laws were broken.
"Our national environmental laws don't require our environment minister to properly evaluate the impact of 4.6 billion tonnes of pollution on the Great Barrier Reef and other world heritage areas," he said on Friday.
"It's like approving a mine for asbestos without having to consider the impact of that asbestos on the health of human people"
Mr Sinclair said the only way the project in Queensland's Galilee Basin could now be halted was through the "passion, commitment and determination of the Australian people".
But Environmental Defenders Office Queensland chief executive Jo Bragg said it could appeal over this latest ruling in the High Court of Australia.
"That's an option only to be exercised rarely and which is never exercised without very careful consideration," she told AAP on Friday.
Ms Bragg could not confirm if this was the last legal option open to opponents of the Adani coal mine, which would be the largest in Australia.
"We're still very much examining all aspects of the project and its lawfulness," she said.
Adani Australia chief executive Jeyakumar Janakaraj welcomed the Federal Court's two rulings against two "dissenting" minorities in a statement on Friday.
Mr Janakaraj said the $22 billion project would create "10,000 direct and indirect jobs", with a minimum 7.5 per cent of those going to traditional land owners.
