The Senate gave bills to establish the JobKeeper program approval on Wednesday night, paving the way for up to six million employees to receive the cash.

Businesses will be given the money to pass on to workers as the government desperately tries to save millions of jobs during the coronavirus pandemic.

Prime Minister Scott Morrison said the scheme was the biggest economic lifeline in the nation's history.

"Today is about defending and protecting Australia's national sovereignty," he told parliament.

More than 730,000 businesses have registered for the program since it was announced last week.

Firms will be eligible if they can demonstrate a 30 per cent virus-related turnover hit, with the threshold set at 50 per cent for companies turning over $1 billion.

All full-time and part-time workers will be covered, along with casuals that have at least one-year link to their company.

Sole traders and New Zealanders on 444 working visas are also included.

Labor and the Greens argued for changes to the scheme to include more casuals and migrants on temporary work visas, arguing more than one million people in each cohort would be excluded.

"Many needy Australians will miss out," Opposition Leader Anthony Albanese told the lower house.

But the government rejected the push, insisting a line had to be drawn somewhere.

Labor's lower house amendments failed, with the coalition holding firm against broadening JobKeeper.

Many who are not eligible for JobKeeper can potentially access $1100 a fortnight in dole payments, which have been temporarily doubled during the crisis.

Finance Minister Mathias Cormann said the government's economic measures were extraordinary in scale and size.

"The JobKeeper package is one piece of the bridge we are building together to the other side of this crisis," he told senators.

Labor urged Treasurer Josh Frydenberg and Social Services Minister Anne Ruston to use their extraordinary powers to adjust wage subsidy and welfare payments to help migrants and casuals.

"With the stroke of a pen, treasurer Frydenberg can fix issues with JobKeeper, and minister Ruston can fix issues with JobSeeker," opposition Senate leader Penny Wong said.

The government also rebuffed calls to include council workers in the wage subsidies, arguing they were a state responsibility.

Under late changes to the bill agreed between unions and the government, workers who have their hours cut will be able to request time to work a second job.

The Fair Work Commission will be able rule on worker disputes with employer behaviour including stand-down periods and changes to people's work location or duties.

Workers can agree to change their days, while bosses could also ask for annual leave to be taken, provided employees have two weeks left over.

The Greens and fellow minor party Centre Alliance's upper house amendments were doomed after Labor opposed making changes in the Senate to allow for the bill's urgent passage.

But the Senate established a Labor-chaired select committee to scrutinise all aspects of the government's coronavirus response.

Australian Associated Press