The sitting fortnight due to start on August 4 was cancelled on the weekend after advice from the acting chief medical officer.

"[The medical advice] was it was not a good sense to bring people from all over the country, particularly from Victoria, and to create that risk. Not just for the ACT, but more broadly," Mr Morrison said.

"We will continue to manage these risks carefully and exercise our response abilities carefully."

Mr Morrison said he would be seeking for Parliament to return in person on August 24, and that being in person was "an important part of how our Parliament functions".

Acting Chief Medical Officer Paul Kelly described federal parliament as a "mixing pot".

"Parliament House is a very big mixing pot for the whole country when you consider where people come from, both parliamentarians and their staff coming to Canberra, mixing, meeting and so forth," he told ABC radio.

"It is very difficult to keep those physical distancing requirements."

Many people have pointed out employers around the country have moved to online workplaces during the coronavirus pandemic and questioned why parliamentarians don't do the same.

Professor Kelly said the work of politicians continued, even if they did not meet in person.

"Parliamentarians are continuing to work in their electorates, absolutely, and the government is continuing to work," he said.

Professor Kelly also warned more sitting weeks could be cancelled.

"At this stage it's a two-week delay, and that will be reassessed as that time comes closer."

Earlier Labor had been pushing for Parliament to return to Canberra on August 24, calling for health protocols to be developed to allow MPs and senators to return to the capital, even if Victoria and parts of NSW continue to face increased coronavirus cases.

Prime Minister Scott Morrison announced on Saturday the next parliamentary sitting fortnight had been cancelled due to the rate of community transmission in Victoria and parts of NSW, and the risk caused by MPs and staffers travelling to Canberra.

While Labor supported the decision, leader Anthony Albanese said additional Senate estimates hearings and additional meetings of the Senate COVID-19 committee would be needed to ensure proper scrutiny of government decisions.

Now Labor's manager of opposition business in the House of Representatives Tony Burke and manager of opposition business in the Senate Katy Gallagher have written to speaker Tony Smith and Senate president Scott Ryan proposing a working group to ensure plans can be made to guarantee sitting weeks go ahead.

"With five weeks between now and the next scheduled sittings of 24 August, we have the time and the opportunity to determine the arrangements and health protocols that would allow Parliament to sit, should the health challenges be ongoing," Mr Burke and Senator Gallagher wrote.

"It must always be the aim to hold Parliament in person in Canberra wherever possible, so that the government can be held to account, and democracy can continue to operate as normally as possible."

The proposed working group would include the presiding officers, acting chief medical officer Paul Kelly, ACT chief health officer Kerryn Coleman and the government and opposition managers of business in each chamber.

Independents and the Greens have criticised the decision to completely cancel the sittings, with Greens leader Adam Bandt calling for virtual means of sitting to be explored, as well as push for an elimination strategy to reduce cases of the virus. Centre Alliance senator Rex Patrick called for the sitting weeks to be rescheduled for September.

Despite the push for virtual sittings, Labor believes it is possible and preferable for Parliament to sit in person.

"Parliament has already achieved the very difficult task of holding in-person sittings during the pandemic, and has done so without jeopardising the health of those inside Parliament House or residents of the ACT," Mr Burke and Senator Gallagher said.

"No doubt, the current situation presents new and complex challenges, but these challenges should not be viewed as insurmountable."

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As a senator for the ACT, Senator Gallagher acknowledged on Sunday the fears in the community about the risks that a large number of interstate travellers could bring.

"Canberrans have a right to be as safe as they can be in their community as any other community and at the moment, it appears on the medical advice that that can't be guaranteed," she told reporters.

But Senator Gallagher said her experience in chairing the Senate committee into the COVID-19 response through videoconferencing showed it wouldn't be possible to run Parliament in the same way.

"When you look at the nature of some of the work that's being done here, like debating legislation and amendments and things like that, I think would get quite tricky on video-conference," she said.

"But I think, at the end of the day, we need to put in place things that are going to make the Parliament safe so that the Parliament can sit, because the Parliament can't get cancelled every time there's an outbreak, if what we're being told by the medical experts is that outbreaks are going to continue to occur."

Federal Parliament was due to sit from August 4 to August 6, and then from August 10 to August 13, but the next scheduled sitting now starts on August 24.

At a press conference on Saturday afternoon, Professor Kelly said the logistics of a parliamentary sitting made it "high-risk".

"By the nature of their work, even with physical distancing, hygiene, and all the other measures we put in place ... here is a large number of people from all over Australia converging in one place for an intense period," he said.

Professor Kelly said he had been speaking with Dr Coleman about the issue in recent weeks. He said Mr Morrison had specifically sought advice on Friday.

Asked what would need to change for him to feel comfortable that politicians and staffers could safely enter Canberra, Professor Kelly said "substantially lower rates of community transmission and signs of control" of the Victorian wave and "no worsening" in the latest outbreak in south-west Sydney.

The upcoming fortnight would have been Labor's first chance to question the government in Parliament on its plans for the future of the JobSeeker and JobKeeper payment schemes, which Treasurer Josh Frydenberg was due to outline in an economic statement in Canberra on Thursday.

Professor Kelly said Mr Frydenberg, who lives in Melbourne, will be able to travel to Canberra for the speech. But the treasurer will be restricted in "what he can and can't do" while in the capital.