The massively underspent JobKeeper scheme could be used to support the battered tourism sector, while the government remains firm it won't be expanded to workers who missed out.
Finance Minister Mathias Cormann said the six-month wage subsidy scheme was working as expected, despite a $60 billion forecasting error.
Just 3.5 million workers have been enrolled for the $1500 fortnightly payments, rather than the 6.3 million that Treasury had estimated and budgeted for.
Treasury relied on epidemiological data when designing the $130 billion package.
But Health Minister Greg Hunt insists the nation's health experts are not to blame for overestimating the impact of coronavirus.
"What we have done is planned for the worst and been able to deliver the best," he told reporters in Canberra on Monday.
Treasurer Josh Frydenberg has no plans to make wholesale changes to the scheme.
But he could use the unspent money to extend JobKeeper payments beyond six months for tourism operators.
The program, which was designed to keep people connected to workplaces smashed by coronavirus restrictions, will be reviewed next month.
"The tourism sector could be one sector in need of further support," Mr Frydenberg told the ABC.
"That's what we'll look at in the context of the economic situation at the time."
Mr Frydenberg and the prime minister have both taken responsibility for the forecasting mistake.
Labor frontbencher Joel Fitzgibbon described the blunder as the biggest budget error since federation.
"Given they thought that $130 billion was a reasonable investment, then surely there's an opportunity here to adjust the scheme to extend it for some who have missed out," he told the Seven Network.
Arts and entertainment workers, university staff and many casual employees have been deliberately excluded from the scheme.
Senator Cormann is staring down pressure from unions and business groups who want the scheme to include more workers.
"It is still an extremely expensive program - $70 billion is a lot of money," he told ABC radio.
Nationals MP Barnaby Joyce is against the idea of expanding the program.
"It's like finding out you've got an extra $20,000 on your credit card," Mr Joyce said.
"You just say 'oh beauty, I'll go out and buy electrical goods and clothes'. This has got to be paid back."
Shadow treasurer Jim Chalmers said the accounting error had been catastrophic for hundreds of thousands of Australian workers.
Australian Associated Press