The Morrison government has defended excluding more than one million casual workers from $1500 a fortnight in coronavirus wage subsidies.

Finance Minister Mathias Cormann says casuals not covered under JobKeeper will be able to access the $1100-a-fortnight JobSeeker allowance and other welfare benefits.

“The JobKeeper payment is taxable. The JobSeeker payment isn’t,” he told Sky News on Tuesday.

The $130 billion scheme will be passed when parliament sits on Wednesday.

Drafting of changes to workplace law are expected to be finalised on Tuesday after Industrial Relations Minister Christian Porter struck a deal with ACTU secretary Sally McManus.

While unions pushed for changes to be made through the Fair Work Commission, the government will instead legislate temporary amendments to the Fair Work Act.

It’s expected unions will be given an assurance they can pursue employer wrongdoing through the commission.

Labor’s industrial relations spokesman Tony Burke believes there will changes to the legislation to allow a FWC role.

“We’re not going to let the perfect be the enemy of the good. But we are arguing that people shouldn’t be left behind,” Mr Burke told Sky News.

“They say you’ve got to draw the line somewhere, but they’ve drawn a very strange line.”

Labor will back the legislation but are likely to push for changes in parliament.

While the JobKeeper payment is expected to cover six million people, 1.1 million casuals who have been with their employer less than a year are set to miss out.

Another 1.1 million temporary migrant workers are also not covered.

There’s mounting pressure from more than 120 faith, union, business, civil society and migrant groups to include overseas workers.

Acting Immigration Minister Alan Tudge said temporary visitors needed to look after themselves during the crisis.

Mr Tudge said sacked migrant workers would have to go home unless they could find another sponsor.

Migrant Workers Centre director Matt Kunkel said the vast majority of people on temporary visas couldn’t go home because of closed borders or not being able to afford an airfare.

“We cannot afford to leave anyone behind,” he said.

The National Retail Association, National Council of Churches in Australia, Migration Council of Australia and the Federation of Ethnic Community Councils of Australia support the call.

Unions and welfare lobby groups are also behind the push.

In full-page newspaper advertisements on Tuesday, the group called on Prime Minister Scott Morrison to show leadership and help migrant workers.