Senior cabinet minister Peter Dutton has been forced into home quarantine and will miss the upcoming fortnight of federal parliamentary sittings.
The Queenslander's sons attend a school subject to state health authority directions about a growing coronavirus outbreak.
Mr Dutton, who was the first government member to contract the disease in March last year, will isolate at home with his family for two weeks.
"Having had COVID and being fully vaccinated, I have also tested negative this morning," he said in a statement on Monday.
The defence minister will remotely continue his cabinet roles including leadership, national security and expenditure review committee meetings.
Christian Porter will act as leader of the house in Mr Dutton's absence.
Opposition Leader Anthony Albanese will be allowed to attend parliament under tight restrictions after being in Queensland before arriving in Canberra.
A growing cluster in the state's southeast has sparked a lockdown extension until at least Sunday afternoon with six schools considered high-risk exposure sites.
Mr Albanese must wear a face mask when moving around parliament except when speaking in the lower house chamber.
The Labor leader is allowed to conduct news conferences in outdoor areas of the building but is required to isolate at his Canberra residence when not at parliament.
He is largely restricted to his office.
Queensland MPs who have travelled to the ACT for the upcoming sitting period are subject to the same conditions.
Prime Minister Scott Morrison will emerge from similar arrangements on Tuesday after being restricted to The Lodge and parliament for the past two weeks since arriving from Sydney.
With sittings scheduled for four of the next five weeks, the political battle is expected to be centred on the federal government's pandemic response.
Mr Albanese's mantra is the prime minister had two jobs - the vaccine rollout and effective quarantine - but botched both.
Mr Morrison said Australia had outperformed the world on stopping the disease from running riot.
"If we had the same fatality rate of COVID as countries just like us across Europe, the United States, the United Kingdom, there would be 30,000 more people dead in Australia right now," he told 5AA radio.
"We avoided that and we prevented that together with the Australian people."
He said the country's economic future and national security would be a focus of the election, which is due to be held by May.
