There is a push to squeeze more from gas companies into the public purse as profits soar.
Proposed changes to the Petroleum Resources Rent Tax announced as part of the federal budget will claw back an extra $2.4 billion over the next four years.
Crossbenchers are calling on the government to go further instead of tinkering around the edges, as well as look into a resource rent tax.
Standing alongside other 'teal' crossbenchers, independent MP Allegra Spender said the changes didn't come close to giving Australians their fair share of record profits from resources being sold overseas.
"There was $40 billion extra raised in terms of the revenue last year from these gas companies," she told reporters in Canberra.
"This change is going to collect little more than one per cent of that each year."
The Wentworth MP said the government needed to take the pressure off workers propping up the budget through higher income taxes.
"If you just fiddle with these taxes, then you miss the opportunity to make a wholesale change to how we tax resources in this country," she said.
"To rebalance away from workers, away from Australian families and to get the full benefit of the Australian resources."
Independent MP Sophie Scamps said the public was being dudded out of tens of billions of dollars.
"These resources are being given away on the cheap to multinationals who are not paying their fair share of tax," she said.
Ms Spender added that tax reform now through a resource rent tax as the critical mineral sector grows would also position Australia to benefit into the future.
"With the boom in critical minerals and lithium that is going to happen in the next generation and wealth that we could create for the Australian taxpayer, if we don't get on with a resource rent tax then we are absolutely failing the next generation."
The Greens also want the government to go further, saying the changes only bring forward some revenue and don't claim an extra dollar in tax.
The minor party says it's not good enough when the gas companies are happy with the changes which would bring in less than the revenue from the indexation on HECS and student debts.
"It is an utterly broken tax system," Greens senator Nick McKim told ABC radio.
"What's very instructive is the gas cartel loves it."
The Australian Petroleum Production and Exploration Association said the changes provide greater investor certainty for the industry.
"This outcome also closes out the long-running Callaghan review ... and will ensure the ongoing efficiency and administration of the PRRT regime," chief executive Samantha McCulloch said.