University management and union representatives have separately told senators on Tuesday the sector is on track to shed 21,000 full-time equivalent jobs by the end of the year, which could mean up to 30,000 people.

Universities Australia head Catriona Jackson says 3000 job losses have already been announced.

"I have no doubt we'll get close to that 21,000 number by the end of this year or very early next year," she told a Senate committee examining the government's response to the COVID-19 crisis.

"It's quite clear that we have not a one-year problem but a two-, three-, four-year problem."

The government has guaranteed universities it will fund the expected number of domestic student places throughout 2020 even if some drop out.

However, it has made three changes to JobKeeper rules that exclude public universities.

"Obviously it would have been very substantial for those universities who are facing thousands and thousands and thousands of job losses, they would have been able to lessen the number of job losses quite substantially," Ms Jackson said.

National Tertiary Education Union research officer Terri MacDonald said universities had been asking the government for assistance since February, when it became clear travel restrictions would severely limit the numbers of international students.

"It's worth noting that private higher education providers, which do have JobKeeper, have been able to save around 5000 jobs," she told the committee.

The union says two-thirds of university staff are in insecure employment, including most of the research workforce.

"What that means when we hit a bump in the road like this, the first thing universities do is they look to their staffing cohorts and they start to shed," Ms MacDonald said.

"That has a roll-on impact in terms of the subjects that can be offered ... and we're even looking at campus closures, particularly in some of our regional institutions."

Monash University vice-chancellor Margaret Gardner, who chairs the Group of Eight research-intensive universities, said there were thousands of researchers on fixed-term contracts tied to funding grants due to end within the next year.

She also defended universities from charges they had become too reliant on Chinese students, saying the sector was no more dependent on China than Australia's other major export industries.

"It is very unusual to be criticised for actually creating one of Australia's most successful service exports. I would have thought that was something we should celebrate" she said.

The sector forecasts it will lose $16 billion over the next four years, about three-quarters of which is down to international students being unable to attend campuses.

Australian Associated Press