NSW's highest court has banned a protest on Aboriginal deaths in custody, which was expected to draw thousands to the Sydney CBD, because it breached coronavirus restrictions.
From 1:45pm today, that decision is being fought in the NSW Court of Appeals.
About 5000 people are expected to rally at Sydney Town Hall at 3pm today in honour of African American man George Floyd and over 420 Indigenous Australians who have died in police custody since the Royal Commission into Aboriginal deaths in custody - including Dunghutti man David Dungay Jr.
Supreme Court Justice Des Fagan on Friday declined to approve the Stop All Black Deaths in Custody rally, organised by Raul Bassi, as an authorised public assembly.
Before the decision, Mr Dungay's mother Leetona Dungay vowed she would march regardless of the ruling.
"I'm marching for my son and nothing is stopping me," Ms Dungay said outside the court.
"If we don't march tomorrow that means they'll keep killing people."
Police had earlier successfully argued Mr Bassi had not given the required seven days' notice for an assembly of 5000 people.
Justice Fagan said he appreciated the rally's central issue and that it was designed to be concurrent with similar events in other countries.
"I don't diminish the importance of the issues and no one would deny them in normal circumstances," he said.
"No one denies them that but we're talking about a situation of a health crisis."
Other countries hadn't respected coronavirus and had suffered "markedly worse" than Australia, he said.
Australians had also given up their livelihoods, pursuits, endeavours and rights to worship to help halt the spread of COVID-19, the judge said.
"Everyone has given up a lot in order to defeat the disease on the basis that this is best advice health officials have given us," he said.
"A great many people have lost their livelihoods for the time being ... people have been unable to attend funeral services for loved ones."
Mr Bassi said he and police agreed on Thursday the protest could go ahead.
NSW Chief Health Officer Kerry Chant told the court a protest of 10,000 could "increase the risk of community-acquired infections and the seeding of clusters".
Police originally asked the court to rule invalid a document Mr Bassi had given them a week ago advising 50 people would attend a vigil near Central Station.
That first notice of intention to hold a public assembly was significantly rewritten on Thursday to state 5000 people were expected to gather at Town Hall at 3pm for a cultural ceremony and speeches before a 900-metre walk to Belmore Park.
Mr Bassi told the court he had organised about 100 rallies, some with 50,000 people, and had expressed to police on Thursday he was concerned the original space wasn't big enough.
Police then agreed to a change and sent him an amended notice, he said.
Justice Fagan said the second rewrite was "entirely different" to the May 29 notice and hadn't received police approval.
That left Mr Bassi requiring the court's explicit permission.
The judge rejected the police concern that the protest risked "inciting violence and other forms of unlawfulness", saying he had more confidence in the local community not to replicate events seen in the United States.
But he said he couldn't authorise a gathering of 5000 people in times where normal gatherings of more than 10 people are banned as a result of health advice.
"The court's authorisation would amount to a defiance of the judgment made by the ministers in the government (and their experts) acting in the interests of the safety of all," he said.
This story is developing as the appeal is heard.