Employers who sack staff to take advantage of taxpayer cash for hiring young workers could be excluded from the wage subsidy scheme.
Corporations found to have underpaid workers or recently paid dividends to shareholders could also be cut out.
The Senate will soon consider whether to reward businesses for hiring unemployed young people after legislation underpinning the program cleared the lower house.
Greens leader Adam Bandt claims the Morrison government is simply setting up a slush fund for wage thieves.
"In the biggest recession we've seen in generations, we shouldn't be subsidising profitable corporations or giving public money to corporations that underpay workers," he said on Tuesday.
"If a big corporation is doing well enough to pay dividends during a pandemic, it doesn't need the public to pay part of its wages bill."
The Greens are also concerned the youth wage subsidy scheme could further fuel casual and insecure work.
"We need to see the details to make sure this wage subsidy won't make the employment crisis worse," Mr Bandt said.
"The government already seems confused about whether the scheme would allow employers to fire a decently paid full-time employee in order to recruit two young people on a subsidised minimum wage."
The Morrison government has been badgering Labor to support the hiring credits since they were outlined in the budget.
Labor called the coalition's bluff by pulling off a tactical manoeuvre and quickly pushing the bill through the House of Representatives.
The bill will not get debated in the Senate until at least November 9, as budget estimates hearings are scheduled for this fortnight.
Under the plan, employers that take on jobless people aged under 30 will receive $200 a week, while those who hire people aged 30 to 35 will receive regular payments of $100.
The federal government expects the $4 billion program to help create 450,000 jobs over the next 12 months.
Opposition Leader Anthony Albanese said Labor had no problem with young people being given support but was concerned 928,000 jobless people aged over 35 would miss out.
The prime minister argues young people have been four times more likely to lose their jobs or have their hours cut during the coronavirus pandemic, and will spend years on the dole if they do not return to work quickly.
Australian Associated Press
