The Greens will demand that the party hoping to form the next federal government spend billions to "restore nature", if the election ends with a hung parliament.
As a rising number of voters turn away from the two major parties, the May 3 poll could end with neither winning the majority of seats needed to govern in their own right.
This would leave the Greens, along with 13 crossbench MPs made up mostly of teal independents, holding the balance of power.
However, the Greens' bargaining chips are likely to be offered to Labor alone, given leader Adam Bandt's decision to rule out supporting any coalition bid to form government.
Under a policy announced on Wednesday, the Greens want at least one per cent of the federal budget to be used to protect Australia's environment, prevent extinction and arrest biodiversity decline.
This equates to about $8 billion in 2025/26, against total expenditure in the budget of more than $785 billion.
It would provide an extra $17 billion in "investment in nature" over the forward estimates, or double current government expenditure, according to Parliamentary Library research cited by the Greens.
"Nature needs us, the forests need us and the koalas need us," Greens environment spokeswoman Sarah Hanson-Young said.
"This election is vital for saving our environment."
Mr Bandt also wants an incoming minority government to expand Medicare-covered dental services to all Australians, echoing the Greens' successful push in 2010 to include children's dental care in Medicare under the minority Gillard Labor government.
The Greens also want taxes on big corporations, the protection of koala habitats, a halt to native forest logging and greenwashing to be made illegal.
For many voters, action on climate change has been playing second fiddle to their cost-of-living concerns.
But Labor's actions, which weakened Australia's environmental protections in favour of Tasmanian salmon farming jobs, during the last parliamentary sitting week brought the issue back to the public consciousness.
The government was elected in 2022 promising to act on climate and, specifically, to reform Australia's environmental law.
However, the changes have been beset by delays and political games, with Prime Minister Anthony Albanese overruling his environment minister in November to scupper a deal that would have helped create a national Environment Protection Agency.
As a result, the Greens have vowed to use its post-election position to force the hand of a new government.
"Labor will break their promises again unless there are more Greens there to hold them to account and get them to act," Mr Bandt said.
The minor party is hoping to wrest the Adelaide seat of Sturt from the Liberals, alongside some of Labor's inner-city Melbourne seats.
It's also attempting to sandbag support at three urban Brisbane electorates.
