Western Australia's government has been accused of failing to learn from other states amid confusion about mask-wearing requirements for hotel quarantine workers.
After two days of intensive testing, WA is yet to detect any new COVID-19 cases linked to a hotel security guard who roamed the streets of Perth while infectious.
Metropolitan Perth, the Peel region and South West are set to exit a five-day lockdown on schedule at 6pm on Friday if no further cases are detected.
Questions remain unanswered about the breach at the Sheraton Four Points quarantine hotel, including whether the security guard behind the outbreak was wearing a mask when he delivered medication to a sick guest.
But Health Minister Roger Cook has revealed guards are not expected to wear a mask at all times, even while on the same floor as confirmed COVID patients.
Opposition Leader Zak Kirkup has called on the government to enforce mask-wearing for such workers at all times within hotels.
In his most stringent comments since becoming leader of the Liberals late last year and pledging a unity ticket on the health response, Mr Kirkup accused the government of complacency in its handling of the pandemic.
"We have a five-day lockdown because the hotel quarantine system failed," he told reporters on Wednesday.
"The West Australian government ... should have been in the best possible position to prepare for this and to learn from every other state and territory about the risks when it comes to our hotel quarantine arrangements.
"Unfortunately by the health minister's own admission, this has failed."
Mr Kirkup denied he was seeking to politicise the crisis ahead of the March 13 election, which the Labor government is predicted to comfortably win.
"Our unity ticket has always been to back in the chief health officer's advice and that doesn't change," he said.
Genomic testing has linked the guard's case to the same highly contagious UK variant present in two recently returned overseas travellers.
He is believed to have delivered medication to one of the travellers who was accommodated on the same floor on which he was working on January 24.
Pressed repeatedly on Tuesday, Mr Cook was unable to say whether the guard had been wearing a mask.
He added the government would review whether hotel security guards should be required to wear a mask at all times.
The family of the guard, a man in his 20s dubbed "case 903", has told The West Australian newspaper he has no serious symptoms but is distraught about having potentially infected others.
Contact tracers have identified 151 close contacts and 68 casual contacts, 104 of whom have returned negative tests.
The government is yet to reveal what restrictions might remain in place beyond the lockdown, although schools are expected to return next Monday.
