Mr Bandt said it would be "better for the country" if the Albanese government reversed its stance on both fronts, but said if it didn't then the Greens stood to gain at the next federal election.

"If the government is still opening new coal and gas and still giving tax cuts to billionaires then people will know it is because Labor wants it," he said.

"The answer to that is to vote more Greens in."

Mr Bandt made the comments in his first wide-ranging interview with ACM since the Greens' historic federal election result, where it picked up three lower house seats in Brisbane and secured the balance of power in the Senate.

The Greens leader said the Labor-held seat of Canberra would be firmly in his sights at the next poll due in early 2025, describing the record haul from this year's election as a "floor not a ceiling" on what the left-wing party could achieve.

In the interview, the 50-year-old also laid out the next steps in the Greens' fight to stop new fossil fuel projects, the urgent need for an authority to help coal miners transition to new industries and the cost-of-living relief which must be included in next month's federal budget.

The fate of the Albanese government's progressive legislative agenda rests in the hands of the Greens, whose 12 upper house votes it needs to pass bills which Peter Dutton's Coalition opposes.

The first real test came on the government's bill to enshrine its 43 per cent 2030 emissions reduction target and net zero by 2050 goal in law.

Having infamously sunk former Prime Minister Kevin Rudd's emissions trading scheme in 2009, there was speculation the Greens could again torpedo Labor's plans.

But despite attacking the 43 per cent target as far too low, and amid some internal tension, the Greens resolved to support the bill after Climate Change Minister Chris Bowen agreed to some tweaks.

That includes provisions which will require government agencies to factor in the new climate targets in its decision making.

"Our view is that it will make it harder for them [agencies] to use public money for fossil fuel projects," Mr Bandt said.

The decision to support the bill was in keeping with Mr Bandt's pre-election commitment to use balance of power to improve, rather than block, the government's agenda.

Mr Bandt told ACM that once it was clear that Labor wouldn't accept their demand for a moratorium on new coal and gas projects, the Greens decided to support the targets and continue the campaign elsewhere.

While some hardcore members would have preferred the Greens torpedo Labor's "weak" emissions reduction target, Mr Bandt said supporters could see that his team was "trying its hardest" to win the longer-term fight - pushing Australia out of fossil fuels.

The fight now shifts to two new battlegrounds: the redesign of the scheme intended to limit pollution from the nation's heaviest emitting facilities, the so-called "safeguard mechanism", and a looming rewrite of federal environmental protection laws.

The Greens, as well as ACT senator David Pocock, are also trying to force Labor to exclude plug-in hybrids from its EV tax cuts bill, arguing it amounted to handouts for fossil-fuel powered cars.

Mr Bandt sees the safeguard mechanism and overhaul of environmental protection laws, which will need to pass parliament, as opportunities to prevent the opening of new coal and gas projects.

The Greens are pushing for a so-called "climate trigger" to be added the Environment Protection and Biodiversity Conservation (EPBC) Act , which would require the greenhouse gas emissions from a project to be considered during the assessment process.

Mr Bandt has signaled that the Greens could be prepared to vote against Labor's rewrite of federal environmental protect laws, which are expected to be drafted next year, if a trigger isn't included.

"We haven't had that discussion as a party room, but it's difficult to see how the Greens could support a new set of environmental protection laws that didn't take climate change into account," he said.

The Greens are also calling for a new government authority to support coal miners transition to new industries, an idea which has broad support across the union and environmental movement.

Under the Greens' transition plan, the government would offer a 50 per cent wage subsidy to a businesses which took on an ex-coal miner, guaranteeing them a job at the equivalent pay for a decade.

"In the election contest, Liberal and Labor [politicians] were turning up in coal and gas communities in hi-vis vests saying 'don't worry, coal and gas have a future for the next 50 years," Mr Bandt said.

"The workers in communities who live there know that is not the case. They know change is coming, and they just want politicians to stop lying to them about it."

Treasurer Jim Chalmers has promised a "bread-and-butter" budget on October 25 as he manages a set of books saddled with a $1 trillion of public debt and an economy facing stiff headwinds.

Labor's election promises for cheaper childcare and medicines are shaping up as the only cost-of-living relief measures in the budget, after Dr Chalmers ruled out extending the fuel excise cut beyond this week.

With inflation tipped to nudge 8 per cent by the end of the year, Mr Bandt is pushing the government to do more to support households.

He said it should start with expanding Medicare to cover dental, a policy which the Parliamentary Budget Office [PBO] estimated would cost $77 billion over the course of the decade.

Mr Bandt disputes that this and other Greens' policies are unaffordable and therefore unrealistic, insisting they could be paid for with the money freed up from abandoning the stage three income tax cuts.

Greens-commissioned PBO analysis calculated the tax cuts would cost $243 billion over the next 10 years - although some experts have questioned if it would be that much.

The government has so far rejected calls to dump the tax cuts, but Mr Bandt plans to keep fighting.

"Part of our job in parliament is to push the government to change its mind on bad policy - including stage three tax cuts," he said.