Two government agencies are being taken to court in a bid to force them to reveal the full suite of climate harms caused by the fossil fuel projects they fund.
Those behind the landmark case say victory would give taxpayers far greater transparency about how Export Finance Australia (EFA) and the Northern Australia Infrastructure Facility are spending their money as the planet warms dangerously.
It's a first attempt to force compliance with environmental laws requiring all government agencies to report annually on how their activities accord with the principles of ecologically sustainable development.
That includes the precautionary principle, the effect of their activities on the environment - including communities and people - and what steps, if any, they are taking to minimise harm.
Human rights and environmental organisation Jubilee Australia has brought the case, which was filed in the Federal Court of Australia on Tuesday.
It says Australia's export credit agency, EFA, and the $7 billion fund for infrastructure in northern Australia both provide taxpayer-subsidised finance for risky new fossil fuel and related projects.
"The real environmental impacts of their activities are enormous and taxpayers deserve to know," says Jubilee's executive director Luke Fletcher.
"Over the past decade they have given over $1 billion to some of the most polluting fossil fuel projects in the world that will lock in fossil fuel dependency for decades to come and undermine Australia's climate commitments under the Paris Agreement."
He says despite the passage of new climate change laws, both agencies can still support major fossil fuel projects and infrastructure.
Examples include a $164.2 million loan to the Ichthys LNG plant and a $254.7m guarantee for the Gladstone LNG terminal that opened up exports.
"Perversely, they continue to fail to adequately report on how the fossil fuel projects they have made possible impact our climate," Dr Fletcher says.
"There are very real fears that without clearer climate commitments, EFA and NAIF could fund infrastructure in Darwin designed to support a massive expansion of fossil gas such as Middle Arm.
"Or to subsidise some of the world's largest fossil fuel companies such as TotalEnergies and ExxonMobil's Papua LNG project in Papua New Guinea, similar to what EFA has previously done."
David Barnden is the principal lawyer at Equity Generation Lawyers, which is representing Jubilee in the case.
He says the group asked the firm to trawl through the Environmental Protection and Biodiversity Conservation Act, leading to the identification of one provision that's never before been used in a climate action case.
"It appeared to us that the agencies weren't doing a good enough job to inform the taxpayers, which is essentially what this section (of the Act) is for," he said.
"And in terms of environment it's quite a broad definition, which does include communities and people.
"This action could set a precedent for other government entities to report the true impacts of their activities."
The case names five respondents - the two agencies, their current chairs, and one former NAIF chair - as those ultimately responsible for meeting reporting requirements.
Northern Australia Infrastructure Fund declined to comment because legal proceedings are underway.
AAP has also sought comment from the EFA.
Lawyers say a decision in the case could be about a year and a half away.