Premier Daniel Andrews has conceded Victoria's roadmap out of lockdown will likely be redrawn and restrictions could be eased with daily COVID-19 figures in the mid-teens.
The state recorded 15 new cases of COVID-19 on Monday - its fifth-straight day of double-digit infections - but no fatalities.
The state's death toll remains at 810 and the national figure at 898.
Melbourne's 14-day average has increased to 9.9 cases, while 10 mystery cases have been recorded between September 26 and October 9.
Melbourne needed a daily average of five cases as well as five or fewer mystery cases to move to the "third step" of the state government's roadmap out of restrictions on October 19.
While those targets are now unachievable, the premier said some restrictions will still be eased.
"(It) will be broadly on the social space, rather than economic easing, but we may be able to do more on that front in regional Victoria," Mr Andrews told reporters on Monday.
He said the target of a daily average of five cases may be changed.
"It may be at a point where we have to call it, where we have to say that this is as good as it will get - that means there is some greater risk, that means that the task of keeping this thing suppressed will be harder," Mr Andrews said.
"But that's where we find ourselves, and that's the choice that we have to make."
Mr Andrews hit back at federal politicians including Treasurer Josh Frydenberg, who told the Nine's Today Show on Monday the premier needed to "get on with" opening the state and "stop stringing people along".
"I can't stand here and pretend it's over because I desperately, desperately want it to be - that's not leadership. You'd be popular for five minutes and then the hospitals will be overrun," he said.
"All the people calling for us to open up, including some members of the federal government I might add, I don't think they will be standing beside me having to explain why our hospital system is completely overrun.
"You won't see them for dust."
Of Victoria's new cases, 10 are connected to known outbreaks while five are under investigation.
Aldi and Fiesta Market in Altona North and Waverley Gardens Dry Cleaners in Mulgrave were added to Victoria's high-risk locations list.
Meanwhile, a Year 12 pupil at Nazareth College has also tested positive to the virus, scuppering plans to reopen the school.
Some 584,000 primary, secondary and specialist school students returned to the classroom on Monday after 10 weeks of online learning.
Students in years eight to 10 are due to return in a fortnight.
Also, Department of Premier and Cabinet secretary Chris Eccles has resigned after being asked to hand his phone records to the state's hotel quarantine inquiry.
In a statement on Monday, Mr Eccles said the records show he spoke to former Victoria Police Chief Commissioner Graham Ashton at 1.17pm on March 27
After their call, Mr Ashton sent a text message to his federal counterpart, saying a plan had been "set up" by Mr Eccles' department to use private guards in the quarantine hotels.
Mr Eccles is emphatic he did not convey to Mr Ashton any decision regarding the use of security as no decision had been made.
"I was shocked when I was informed last night that this call had been made and that a detailed examination of his records had shown that," Mr Andrews said.
Health Minister Jenny Mikakos resigned last month over her role in the program.
Her replacement Sheena Watt will be sworn into parliament on Tuesday.
The inquiry, led by retired judge Jennifer Coate, is due to hand down its final report on November 6.
Australian Associated Press