Contractors are being carved out of proposed laws to crack down on labour hire workers being paid less.
Employment Minister Tony Burke is working to close a workplace loophole that allows companies to negotiate a rate of pay with their workers and then bring in labour hire and pay them less.
Mr Burke has struck a deal with the resource and energy lobby as he wrangles with business groups and the opposition over the legislation, which they argue will add undue costs to businesses and make operations less flexible.
Service workers - contractors who bring their own machinery and systems compared to worker-only labour hire firms - will be explicitly exempt from the change.
Mr Burke said the estimation of some 67,000 labour hire workers covered by the legislation wouldn't change as his intention was always to exclude service contractors.
But there were concerns it wasn't clear, he said.
"We now will have ... a clear exclusion of service contractors," he told ABC radio on Wednesday.
The Australian Council of Trade Unions says the other provisions, such as making wage theft by businesses a criminal offence and adding minimum pay and conditions for gig workers, would help tackle unpaid overtime.
Casual and temporary workers do almost four hours of unpaid overtime a week, costing someone on the median wage about $6300 annually, it says.
Mr Burke also remained steadfast that he could not bring on four provisions split from the government's bill by crossbenchers.
They include allowing first responders with PTSD to access compensation more easily and protecting workers facing domestic violence.
They passed the Senate after independent senators David Pocock and Jacqui Lambie introduced their own bills with the same wording and got support from the crossbench and coalition.
Mr Burke said given Labor's bill was before a committee that isn't due to report until February, he could not pass the split-off provisions despite calling for the whole bill to be passed as soon as possible.
But the Senate procedure office confirmed they were entirely different pieces of legislation, despite having the same wording.
Mr Burke said it was wrong that people were making submissions to the inquiry but the legislation couldn't be amended to reflect the recommendations.
Rushing through the legislation would be "a shocking way to make public policy", he said.
Senator Pocock criticised Mr Burke's move, saying the minister knew he could add amendments himself.
"There is no obstacle to the government fast-tracking these four measures," Senator Pocock said.
"The government can't have it both ways - on the one hand saying they want the whole bill to pass this year but on the other hand saying they can't pass these four parts because amendments are required."
Senator Lambie called for Mr Burke to "show some good faith and pass them now".
If the four bills aren't passed before parliament rises for the year in early December, first responders and people facing domestic violence will not receive added benefits on the scheduled start date of January 1.