Public transport will be suspended this weekend to prevent protesters travelling to Melbourne's CBD for an anti-lockdown rally.
Victoria Police Chief Commissioner Shane Patton has announced public transport to and from the city will shut down from 8am to 2pm on Saturday, the day of a worldwide series of "freedom" rallies.
Buses will be directed to bypass the city, trams stopped before returning to their junctions and trains turned back.
While acknowledging the move will inconvenience some, Mr Patton said it was designed to avoid a repeat of the violent scenes in last month's anti-lockdown protest and a potential COVID-19 super-spreader event.
"This is a significant step for us," he told reporters on Wednesday.
"We did not take this lightly. We didn't do it last time. But given the circumstances of where we are with the spread of the Delta variant ... we can't afford to allow the transmission of the virus."
The decision to temporarily shut down the network was made in collaboration with Chief Health Officer Brett Sutton, the Department of Health and the Victorian government.
Emergency and essential workers will still be able to travel into the city to get to their jobs, with police finalising alternative transport such as buses.
Barricades, traffic checkpoints and roving patrols will also complement police efforts to create a "no-go zone" for protesters.
"An Uber or taxi is not just going to be permitted to wander into the city," Mr Patton said.
"If there's a need that a worker has required ... an Uber or a taxi, we would make sure that their identification is correct."
Protesters that manage to slip into the city undetected can expect to be arrested and fined $5500 for breaching public health orders.
Some 2000 officers will be deployed as part of Saturday's operation, double the number used for the August 21 protest.
"This will be one of our largest operations we've conducted, I think, since the World Economic Forum many years ago," Mr Patton said.
"This is the biggest game in town for us - to stop this occurring."
Liberty Victoria said it was concerned Victoria Police's "military-style tactics" could be normalised and deployed against "future responsible protests".
"We are also worried that shutting down public transport access to the city will unreasonably affect essential workers and CBD residents," the leading civil liberties body tweeted.
Australian Associated Press