More Defence troops are being deployed to Victoria as the state records hundreds of new coronavirus cases and Melbourne braces for crushing business restrictions.
Victoria recorded 439 new cases on Tuesday and another 11 deaths, bringing the national toll to 232.
Premier Daniel Andrews is introducing harsher penalties to stop people spreading the disease by moving across the state.
More than 500 Australian Defence Force troops are being deployed to Victoria to enforce stay-at-home orders, joined by hundreds more health officials.
Anyone caught breaching isolation orders while infected will be slapped with $5000 on-the-spot fines.
Repeat offenders dragged into court could be fined up to $20,000.
"We will do everything we possibly can to support people but you have got to be isolating when you are directed to do so," Mr Andrews told reporters in Melbourne on Tuesday.
Sick Victorians ordered to stay at home will no longer be able to leave their properties for exercise.
At least 250,000 Victorians will be affected by widespread shutdowns across the retail, manufacturing and construction sectors.
They will join another 250,000 stood down since the pandemic began and another 500,000 working from home.
All non-essential businesses and services in Melbourne will be forced to close or dramatically alter their operations.
Essential businesses including supermarkets, petrol stations, bottle shops, pharmacies, banks and newsagencies will be allowed to stay open.
Construction sites will be forced to scale back and introduce more personal protective equipment.
The prime minister has announced $1500 disaster payments for Victorians who need to self-isolate for two weeks and have exhausted their sick leave.
But unions argue the paid pandemic leave does not go far enough.
The Australian Council of Trade Unions says the payments are less than the average wage and therefore constitute a financial penalty for staying home.
The ACTU also wants the payment extended across the country.
NSW has 12 new cases of the virus on Tuesday, with a high school and primary school in southwest Sydney closed after three students were diagnosed.
South Australia has reported two new coronavirus cases as officials move to reimpose some restrictions on family gatherings and restaurants.
Queensland had no new cases overnight, while another three people have been caught trying to dodge quarantine after travelling to Melbourne.
Victoria's high case numbers have led Tasmania to keep its borders closed until at least the end of the month.
Australian Associated Press