Federal parliament ticked off on the historic JobKeeper scheme on Wednesday night, paving the way for $1500-a-fortnight payments for coronavirus-hit employees.

The tax office will give businesses with a 30 per cent fall in turnover due to coronavirus $1500 for each worker a fortnight, with payments expected to reach employers in the first week of May.

For companies with a turnover of $1 billion, a 50 per cent downturn will be needed to qualify.

More than 730,000 businesses have registered for the program, which will give out money for wages paid from March 30, since it was announced last week.

All full-time and part-time workers are eligible, along with casuals that have a 12-month link to their employer, sole traders and New Zealanders on 444 visas.

Prime Minister Scott Morrison said the government had responded to the coronavirus crisis with the biggest economic lifeline in the nation's history.

"JobKeeper will keep Australians in jobs and it will keep the businesses that employ them in business, both now and into the future," he said.

Labor is concerned that more than two million casuals and temporary migrant workers will miss out on JobKeeper.

Despite the government rejecting amendments to the bill, the opposition still supported the package.

"Never let the perfect be the enemy of the good," Labor leader Anthony Albanese said.

The massive wage subsidy scheme is part of $320 billion in federal spending designed to shield Australia from the coronavirus sledgehammer.

While parliament isn't due to sit again until August, a new Senate select committee has been established to scrutinise the record spending.

Labor frontbencher Katy Gallagher will chair the wide-ranging inquiry.

The committee will have three Labor senators, two government, one from the Greens and independent Jacqui Lambie.

Australian Associated Press