The Victorian government has launched a bid to extend its coronavirus state of emergency for another nine months to December 2021.

Premier Daniel Andrews said it was “always better to err on the side of protecting what we’ve built”, and the move was based on health advice.

He said the state government would introduce legislation this week to keep the emergency powers in place beyond March 15, when they are due to expire. If the bill passes, the powers will be extended in four-week blocks until December 15.

“The sorts of rules that the state of emergency underpins is the order for someone to isolate for 14 days, is the order that means hotel quarantine is mandatory, wearing face masks in certain settings,” Mr Andrews said on Tuesday.

“All of those common-sense things, but particularly hotel quarantine, without a state of emergency, the chief health officer simply has no power to be able to compel people to isolate in a hotel.

“These rules are all about staying safe and staying open.”

Mr Andrews said the legal framework was also important to allow Victoria to continue receiving Australians returning home after being trapped overseas for months.

“That’s why we’ll put this bill into the Parliament today [Tuesday] and we’ll have those good-faith discussions with everybody across the Parliament and hopefully that can pass in an orderly way,” he said.

“Firstly, given 27 days of zero cases, which of course if we can get one more day that’ll be two lots of 28 that we’ve had over recent months,” he said.

“That’s something that no other jurisdiction in the world has done, particularly after a second wave, and should be a point of pride for every single Victorian.”

Tweet from @VicGovDH

The extended period without community transmission of the virus has also prompted the state government to ramp up capacity in Victorian offices to 75 per cent. The ruling – which applies to the state public service and private offices – is effective from midnight on Sunday.

The current levels are 50 per cent for private offices and 25 per cent for the public service.

Victoria has just 22 active COVID cases, all in hotel quarantine. One new hotel infection was confirmed on Tuesday.

NSW confirmed two more cases in returned travellers in quarantine on Tuesday. It also had its 16th consecutive day without locally acquired infections.

Perth hotel Four Points by Sheraton is the epicentre of the WA lockdown.

WA residents wake to second day of lockdown

Meanwhile, up to two million residents of three West Australian regions are beginning their second day of a snap lockdown sparked after a security guard at Sheraton Four Points hotel contracted the highly contagious British strain of COVID-19.

Test results in coming days will reveal whether WA has dodged a bullet with its COVID-19 quarantine leak. No new cases were detected on Monday.

WA’s government took the drastic step after the guard at the Perth hotel contracted the highly contagious strain, then attended more than a dozen venues over several days while infectious.

More than 3100 people were tested on Sunday, most later in the day after the lockdown was announced.

• NSW orders WA returnees into lockdown

Tweet from @WAHealth

Authorities expect most of the guard’s close contacts will have been re-tested by Wednesday. Early tests were negative, and later results will provide clarity about whether the lockdown is likely to end as scheduled at 6pm on Friday.

“If they’re still coming up as negative, that would be a good sign that this person wasn’t a particularly effective spreader,” WA’s chief health officer Andy Robertson said.

“That is what we’re not quite sure on.”

Australian Medical Association WA president Andrew Miller said a decision to extend the lockdown was “50-50”.

“We’re hoping for doughnut days throughout the week – all zeroes – and then perhaps that will be enough,” he said.

“But we will know by then whether we’re looking at a cluster or clusters, which will require a longer period of time, because we know that each cluster usually generates about three weeks’ worth of cases before it is able to be shut down.”

WA Premier Mark McGowan welcomed the initial results but urged people to continue braving long queues and hot weather to get tested.

Anyone living in the lockdown zone across Perth and WA’s Peel and South-East districts, including school students, must stay at home unless shopping for essentials, attending to medical or healthcare needs, exercising within their neighbourhood or working if unable to do so remotely.

Mr McGowan said most people had been compliant despite some “disappointing” panic-buying at supermarkets.

It remains unclear how the guard, aged in his 20s, contracted the virus. He is said to be fully cooperating with a police investigation.

-with AAP