From 11.59pm on Thursday there will still only be five reasons to leave home for Melbourne residents, including Shopping for food and supplies, authorised work and study, care and care giving, exercise and getting vaccinated.
Acting Premier James Merlino urged people to go and get vaccinated, warning if the virus is left to run its course then cases "will explode", adding the government had "no choice" but to extend the lockdown for Melbourne.
"If we don't do this, this thing will get away. This variant of concern will become uncontrollable and people will die. No-one wants to repeat last winter," he said.
Regional Victoria will escape the lockdown extension, with authorities now finalising the details around this change.
It comes after senior government ministers met overnight to discuss the next step for the state. It is understood this included discussion around whether different restrictions will be introduced for regional Victoria.
The highly transmissible nature of the kappa variant is believed to be one of the major reasons for the lockdown extension.
This strain was first detected in India and has since spread to more than 40 countries, with the World Health Organisation (WHO) identifying it as a "variant of concern" as it appears to be much more infectious than other strains.
WHO adviser and University of NSW Professor Mary-Louise McLaws said from an epidemiological perspective, Victoria's cluster was still growing, meaning a lockdown extension is necessary.
"It's growing and it's growing fast and hasn't shown any sign of slowing down," she told news.com.au.
"There should not be any discussion yet of lifting restrictions," she said.
"I can't see them lifting restrictions for another seven days. At the moment this cluster doesn't show any signs of ending."
Testing Commander Jeroen Weimar said at least four of the state's locally transmitted cases have come from "fleeting" contact between Victorians.
"What we're seeing now is people are brushing past each other in a small shop, they are going to a display home, they are looking at photos in a Telstra shop," he said.
"This is relatively speaking, relatively fleeting. They do not know each other's names, and that is very different from what we have been before.
"This is stranger to stranger transmission."
Weimar said this is a feature of the B.1.617 variant, saying it is "quite different" to the kind of transmission Victoria is used to seeing, such as in homes, workplaces or any big social settings.
He said this is the "fastest moving outbreak" to hit Australia.
"This is the biggest outbreak … this year. It is one of the most, certainly the fastest moving outbreak we've seen anywhere in Australia. For a long time," he said.
There are now more than 350 exposure sites across Victoria, with thousands of close contacts already sent into isolation.
