Victorian Premier Daniel Andrews has confirmed all Victorians will be plunged back to stage-4 restrictions following the growth of COVID cases linked to the Holiday Inn outbreak.
He said from 11.59pm tonight all Victoria will go to stage-4 restrictions until 11.59pm on Wednesday.
He said there would only be four reasons to leave their home.
Masks must be worn everywhere outside the home and public and private gatherings are not permitted.
Schools will close as will non essential retail.
Funerals can involve no more than 10 people and weddings are not permitted unless on compassionate grounds.
He said the UK variant of concern was 'so hyper-infection and moved so fast' it was presenting a very real challenge to the state's status.
"Whilst we don't have cases outside those who were notified as close contacts... the way in which they are presenting are a very significant concern to us," he said.
Mr Andrews said by the time someone has tested positive they have already infected their close contacts which makes it incredibly difficult to do contact tracing as there was no gap between one positive and their close contacts testing positive.
He said we must assume there are further cases in the community and it was moving at a velocity that has not been seen anywhere in the country in the last 12 months.
"If we wait for that to be proven correct that's too late and then we will face the prospect of being locked down until the vaccine is ruled out," he said.
Mr Andrews described the new restrictions as a circuit breaker.
"I know this is not the news Victorians want to hear today, I know it's not the place we want to be," he said.
"I am confident this short sharp circuit breaker will be effective and will smother this."