The Australian Workers Union said foreign workers could lose employment if businesses don't offer a goodwill gesture to staff blocked from Australia because of the coronavirus.
The restricted entry for Chinese nationals to protect the Australian public from the deadly virus applies to migrant workers with temporary visas.
The to prevent foreign nationals who have been in mainland China from entering Australia for 14 days.
The government indicated that Australian citizens and permanent residents would still be able to enter, as would their immediate family members.
Home Affairs Minister Peter Dutton on Friday said the government wanted to keep Australians safe from the virus now known as Covid-19.
“I think it's a sensible response, we're really pleased that people up on Christmas Island look like they are all going to be cleared and back home hopefully early next week,” he said.
“So it's a big problem. The numbers are now over 60 thousand. 1370 deaths as of this morning. We'll assess it week by week and we'll do what is in our countries best interests.”
During the announcement of the extension, the federal government said the decision would give businesses, travellers and organisations some certainty.
The Australian Workers Union's Ben Davis was hoping employers would keep positions open for migrant workers who are legally able to work.
“This is something over which these migrant workers and others have no control whatsoever,” he said.
“The humane thing to do is just to wait it out and then they can come back into the country, offer them shifts and offer them their jobs again.”
The Migrant Workers Centre argues the travel ban is putting jobs at risks and it estimates 10 per cent of the workforce is temporary migrants, mainly from China.

Union reps Ben Davis from the AWU Source: AAP
Centre Director Matt Kunkel told SBS News employers were already contacting migrant workers questioning where they are and when they plan to return to their jobs.
“They are losing shifts, they are losing money. Many of these workers are in insecure forms of employment and have very few protections under the law,” he said.
“What it means is once this travel ban is lifted, they are coming back to a situation where they still have to pay rent, they still have to pay all their other costs but they face that with the prospect of not having a job when they get back.”
Mr Davis, who serves as the AWU Victorian branch secretary, said organisations could cut staff because of abandoned employment.
“But there's every chance after certain appropriate advice the federal government could extend it again and again and again, depending on how bad the coronavirus outbreak becomes, so to a point it provides some certainty but I think it's impossible to provide the sort of certainty some people are seeking because there is so much we don't know about the spread of the coronavirus.”
He's said a solution could be to place staff on unpaid leave.
The United Workers Union said if a staff member is unable to come to work because they are stranded overseas, there is potential for an employment contract to be in jeopardy.
Meantime the Maritime Union of Australia is worried its workers will be put at risk when the Kota Nebula container ship arrives after it was granted permission to dock at Darwin.
The union is warning pilots, tugboat crews, linesmen and other port workers will have direct contact with the vessel's crew and be exposed to covid-19.
MUA national secretary Paddy Crumlin said in a called for any ships which docked in China to wait 14 days before they are allowed in Australia.
“The Australian government has imposed strict travel restrictions that prevent air travel by anyone who has been in mainland China in the previous 14 days, yet this container vessel — which visited multiple mainland Chinese ports during this time — is being allowed to simply dock in Darwin.
“Local maritime workers, including those who board the vessel to pilot it into Darwin Port, along with those working to unload it, are all being put at unacceptable risk of exposure through the decision to allow this vessel to dock in breach of the travel ban."

MUA National Secretary Paddy Crumlin Source: AAP
The extension of the travel ban officially begins on Saturday, and will be reviewed in a week.