The military and police officers will enter the areas worst hit by Sydney's virus outbreak to ensure two million residents are complying with harsh lockdown restrictions.
As Sydney prepares to break Thursday's high-water mark of 239 new cases, New South Wales police will begin knocking on doors looking for people in homes other than their own.
Police will also target businesses across the city breaching public health orders, including those in the construction industry allowed to reopen from Saturday.
"You can expect to see more police on the ground, you can expect to see more enforcement," NSW Police Commissioner Mick Fuller says.
"There are a lot of people doing the right thing but this will focus on those who continue to do the wrong thing."
Up to 55 per cent of the 588 cases reported in the past three days have been infectious while in the community.
"We know home-to-home transmission is a huge issue for us, we know people are bringing it home from worksites that aren't complying," Mr Fuller said.
But he stopped short of "random" checks in home, saying police would monitor close contacts and had the power to stop people in public and seek their address.
On Thursday afternoon the police chief formally requested the assistance of 300 defence force personnel for the compliance operation.
On Thursday evening Defence Minister Peter Dutton said in a statement that the requested personnel would deploy from Friday to train over the weekend and on Monday commence working under the direction of NSW Police.
The military has supported hotel quarantine policing, logistics in the Police Operations Centre and compliance during a 2020 border operation.
But its involvement in a civil obedience campaign raised concern for the Australian Lawyers Alliance.
"We understand that public health emergencies require the government to take extraordinary measures but using the military to enforce local laws sets a dangerous precedent," ALA spokesman Greg Barns SC said.
Two million people in eight western Sydney local government areas cannot leave the area unless they are essential workers.
Masks are also mandatory at all times - including outdoors - and people are banned from going more than five kilometres from their home.
Sydney's lockdown enters its sixth week on Saturday, with Premier Gladys Berejiklian admitting cases would rise given the high number of people infectious while in the community.
"We can only assume that things are likely to get worse before they get better," the premier said on Thursday.
But she's rejected suggestions her government failed by imposing restrictions too late and too gradually.
NSW is expected to receive extra support from interstate after an emergency meeting of the Australian Health Protection Principal Committee on Thursday night.
Meanwhile, Sydney Super Dome at Olympic Park will reportedly become a vaccination hub for year 12 students in hotspot areas, ahead of their return to school on August 16.
