Victoria should have gone into a New Zealand-style lockdown at least a week ago, the Australian Medical Association (AMA) President Professor Julian Rait says.
Public health messages are not getting through to people in the state, and stricter messages need to be adopted before the virus gets out of control, Professor Rait told Checkpoint.
He wants masks to be compulsory throughout the state and construction sites and workplaces shut down except for essential workers.
"The tough times we're experiencing in Victoria is because we really haven't locked down hard enough to actually restrict people's movements.
"The AMA in Victoria recommended approximately six days ago that we need to move to a New Zealand style stage four lockdown. And there's a feeling now that of course with cases still rising that that might be necessary.
"I can understand the natural reluctance of government perhaps to embrace that because of the economic consequences, but we seriously feel that unless these additional measures taken to restrict movement, and particularly reduce the amount of people who are in various different workplaces, we think that the cases may still become more and more difficult for the hospital system to manage."
He said he does not think Victoria has reached its peak in new Covid-19 cases.
"I think that the problem is the replication rate is not below the magic number one, and as a result, we're still seeing the cases rising.
"The trend seems to be drifting upwards even though it might be not increasing quite as much as it did at first, before the restrictions. But nevertheless, that has the potential to overwhelm our hospital system.
"We estimate that would take possibly up to 1,600, 1,700 cases a day for a week to 10 days to do that. So we're some way off our capacity in that regard being compromised. But what we're concerned about is the increasing number of healthcare workers who are becoming infected.
"This means those particular staff in the context have to be removed from the workplace and that's creating some considerable stress already on rosters in a number of frontline hospitals."
Professor Rait said one of the main problems in Victoria is the number of people defining themselves as 'essential workers' and ignoring lockdown rules.
"As I understand you [New Zealand] shut down pretty much all businesses, pharmacies, clinics, supermarkets, grocery stores, et cetera.
"But we still have construction sites where they are numerous people working, often commuting in and out from the outer suburbs into these work sites.
"And we're very worried that that could be a problem particularly because 80 percent of all infections identified since July 1 have occurred in workplaces.
"Some of those workplaces might well have been aged care homes or hospitals, but a great many others have occurred in other workplaces, Bunnings Warehouse, for example, hardware stores or that sort of thing.
"So our view is that stage four-style lockdown which restricts people's movement even further would really be desirable now to try and contain this unfortunate pandemic that we're entering in Melbourne."
He said it may be very difficult to change public behaviour in Victoria, where it is estimated 90 percent of people with flu-like symptoms are not isolating prior to getting tested or getting a Covid-19 test result.
"Clearly the public health messages haven't gone through to those people, they're posing a risk to the community.
"The AMA is not really that optimistic that that behaviour can be turned around very quickly unless more strict measures are adopted.
"I think, personally, a New Zealand-style hard lockdown for a shorter period of time would be less painful.
"Difficult though it might be to accept that, I think a more prolonged and lighter lockdown is counterproductive."