Without paid sick leave, casual workers could be caught up in a second wave of COVID-19 outbreaks, according to the South Coast Labour Council.
There is the risk that, without sick leave, casual workers who are unwell may be forced to go in for their shift.
With Victoria recording 112 new cases since Wednesday, NSW South Coast Labour Council secretary Arthur Rorris said that showed the importance of protective measures such as staying home when feeling sick.
The labour council secretary said this could be difficult for casual workers, who may feel compelled to turn up for work - even if they were sick.
"Many of these casual workers have been locked out of JobKeeper and starved of financial assistance," Mr Rorris said.
"If they do not have access to pandemic leave and are feeling unwell this morning what do you think will happen? Tell the boss they can't come in or hide the symptoms and tough it out?"
Victoria and Queensland have introduced a hardship fund where workers who have no sick leave get a one-off payment.
The union movement has called on the federal government to turn this into a national scheme and wanted employers' support.
Illawarra Business Chamber executive director Adam Zarth pointed out casual workers already had compensation for sick leave built into their pay and that employers shouldn't be burdened with the extra "imposition" of providing paid leave.
"However, if the government was to come along and do that, we certainly wouldn't oppose that because we want all employees to be encouraged to be as healthy as possible, to stay away from the workplace if they've got those COVID-like symptoms," Mr Zarth said.