Mining giant BHP is being criticised for saying new workplace laws could cost the company more than $1 billion and risk thousands of jobs.
The federal government is seeking to close a loophole that allows companies that have negotiated a pay rate with workers to then pay labour hire firms less for the same job.
Workplace Relations Minister Tony Burke said it was astounding BHP had put a dollar figure on legislation that hadn't been written.
He said if a company had already decided what a job was worth, it shouldn't be able to undercut other workers.
"That's a loophole and we need to close it," he told reporters in Canberra on Thursday.
BHP says the "same job, same pay" legislation would add to inflationary pressures by "ratcheting up wages without any link to productivity" by interfering with the labour market.
The mining giant's response to the government's consultation paper also branded the policy as being driven "by ideology, not economics" and described it as an overreach.
Mr Burke said the government is also looking at criminalising wage theft and implementing minimum standards in the gig economy as part of its next tranche of industrial relations reforms.
"If you steal from the till it's a criminal offence, if the employee steals from you, it's not," he said.
"That loophole needs to be closed."
Opposition workplace spokeswoman Michaelia Cash said the Albanese government wanted to "effectively abolish labour hire", putting hundreds of thousands of people out of work.
Senator Cash said it was one of a number of proposed industrial relations changes which would "undermine the competitiveness and flexibility of Australia's workforce".
"Mr Albanese needs to respect the employment choices of ordinary Australians and stop his government's attack on labour hire, casual work and independent contracting," she said.
