Around 1200 graduates joined the Australian Public Service in 2020.

A new wave is due to start in February 2021.

But people from the Greater Sydney, Central Coast, Blue Mountains and Wollongong areas have been told not to enter ACT until January 6 due to coronavirus clusters. Travellers who do come must undergo 14 days quarantine.

If the outbreaks worsen, and travel restrictions have to be extended again, Mr Barr said Commonwealth agencies may need to reconsider their arrangements for new starters.

"That will be something that the various public service, Commonwealth agencies will have to be flexible about starting times for new staff," Mr Barr said.

"Remote working will need to be used, I imagine, for some new staff during quarantine arrangements or indeed they will not come at the beginning of the year.

"This will be a case-by-case, department-by-department decision. There's a reasonable amount of recruitment out of Sydney, obviously, for the Commonwealth public service but it's by no means the majority, so I wouldn't say this is a major issue but it is an issue to consider and the employers and employees are going to have to do that."

The Australian Public Service Commission has not published any advice related to the latest coronavirus clusters.

In September, it told agency heads to start getting their staff back to the office where safe, after six months of remote working.

There are currently 1500 people in home quarantine in the ACT.

READ MORE:

Mr Barr said he would not want "tens of thousands of people" to be in self isolation in the ACT.

"That's why we have the very clear message for the people in the COVID-19 hotspots not to travel to the ACT and for Canberra residents not to put themselves into risk by going into those areas," Mr Barr said.

"The only thing I'm certain of is that things can change and change very quickly and it can go in either direction and it can happen on any day, in any week, in any month."