It comes after medical authorities warned the congregation of unvaccinated protesters from Melbourne could become a super-spreader event and on Thursday, Ballarat also experienced its worst COVID outbreak in a month, with another nine positive cases announced.

Paradoxically, Ballarat remains one of the most vaccinated places in Victoria, having passed the 95 percent double dose rate among adults almost three weeks ago and at these uptake levels now likely to be above 98 percent vaccinated.

Police have also announced they are planning a major presence in the CBD on Sunday to curb any possible troublemakers at the 'freedom' rally.

It's not known how many people will attend the event, but a significant amount of Ballarat's CBD is expected to be affected as protesters in what they claim is an attempt to "reclaim Eureka". Today is the 158th anniversary of the Eureka stockade.

Activity online indicates the majority of protesters who have publicly mentioned they will attend will be coming from Melbourne.

On Thursday, another nine positive cases were announced in the city.

In a post on the official Ballarat Police Eyewatch Facebook page, officers urged patience across the city on Sunday.

"Victoria Police expect the following streets to be impacted from around midday until 5pm: Mair Street, Peel Street, Victoria Street, Curtis Street, Little Bridge Street, Sturt Street and Lydiard Street," the post states.

In a statement, a Victoria Police spokesperson confirmed to The Courier there would be a presence in Ballarat on the day "to ensure there are no breaches of the peace".

"We understand that any protest activity in Ballarat has potential to cause disruption to businesses in what will be a busy time leading up to Christmas," they said.

"Victoria Police is engaging with protest organisers and the City of Ballarat in an effort to ensure that any protest activity causes as little disruption as possible."

Both Premier Daniel Andrews and Opposition Leader Matthew Guy have discouraged protest action in Ballarat, while City of Ballarat chief executive Evan King said some council buildings will be closed on the day.

Mr Andrews said "(Eureka) is a very big part of Ballarat's story - no one should be appropriating that".

"Protesting is always an important part of our democratic system but it doesn't work against a wildly infectious virus, protesting won't keep you out of hospital - what keeps you out of hospital is getting vaccinated," he told The Courier.

Mr Guy said he understood people are angry, but "the best way to take that out is at the ballot box at an election".

"It's not to take to the streets, or to attack people for doing their job asking for vax certificates in retail, that's what they've been asked to do and they're just doing their job," he told The Courier.

"It's not to turn on police, who are trying to keep people safe at any time, don't turn on them.

"The best thing people can do if they've got a frustration is take it out at the election, not take it out in wild demonstrations on the street, it's just not helpful."

"Freedom protests" will take place in Melbourne on Saturday and will head to Ballarat on Sunday to commemorate Eureka Day - the Ballarat march was initially planned for Saturday but has since been changed.

Commerce Ballarat chief executive Jodie Gillett said "there is no doubt this will have an impact on our businesses", but noted a Sunday event was preferable compared to a Saturday event.

"It would have caused far more disruption to our business community for the first weekend of December (if it was Saturday)," Ms Gillett said.

"(Businesses) have been through an incredibly tough time and every knock they take is magnified."

She urged employers who may be affected to reach out and "plan accordingly" for their businesses and staff.

The City of Ballarat has pre-emptively postponed children's activities, talks, and a community sausage sizzle to be held at the Eureka Centre to next Sunday, December 12, due to "a separate event planned to be held in the Ballarat CBD", according to a media release.

Chief executive Evan King said in a statement council is "being guided" by police "to understand planning that has been put in place".

"The City of Ballarat's Economic Development Team has also been contacting CBD businesses to ensure they are aware the event is taking place," he said.

"The Eureka Flag is a priceless piece of Australian and Ballarat heritage and history that symbolises our democratic freedoms and the spirit of a fair go for all."

Other official Eureka Day events, including Friday night's Peter Tobin Oration and concert with Goanna's Shane Howard, a Eureka descendant, are still planned to go ahead.

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Earlier this week, Ballarat Health Services expressed concern the event could be a "superspreader event".

"Protests in Melbourne have demonstrated the ability of the virus to rapidly spread in crowds that are not masked or vaccinated," said Dr Robert Grenfell from the Grampians Public Health Unit.

More than 95 per cent of Ballarat residents are fully vaccinated.

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