New South Wales police say they will not hesitate to prosecute those who attend upcoming Sydney protests, citing significant Covid-19 health and safety concerns. Assistant Commissioner Mick Willing said a planned protest connected to the Black Lives Matter campaign was unauthorised because police had not been formally notified. The action is scheduled for Sydney Town Hall on Friday evening, with more than 1,000 people saying they will attend, according to the event’s Facebook page. Willing said police would deploy “significant resources” to enforce the existing health order banning mass gatherings, which could include people being moved on and potentially arrested. He also welcomed the NSW supreme court’s decision on Thursday night to block a refugee rights protest scheduled for Saturday. The rally, which was being organised by the Refugee Action Coalition, was scheduled to take place at the Town Hall on Saturday afternoon. “While the NSW Police Force recognises and supports the rights of individuals to exercise their right to free speech in normal circumstances, these are not normal circumstances,” Willing said on Thursday. “I want to be clear about this – if people choose to break the law and attend this protest, police will not hesitate to take the appropriate action against them.” Justice Michael Walton – who granted the NSW police application for the protest to be declared a prohibited public gathering – said public health risks did not “outweigh the rights of public assembly and free speech”. The NSW police minister, David Elliott, also welcomed the supreme court’s decision on Thursday night and said people could expect to be arrested for disregarding police officer directions. “I urge those thinking of protesting despite the Supreme Court decision and against the health advice to promptly reconsider their plans,” Elliott said. The police commissioner, Mick Fuller, said people attending rallies could be issued $1,000 fines. Immediately after the court’s decision, an RAC spokesman said the ruling would not change the group’s plans. “We’ll still be holding an event this Saturday, urging people to participate,” James Supple said outside court. “As the court said, it doesn’t actually make it illegal to come to a protest, it just gives the police more powers. “We’ll be doing everything in our power to ensure it’s a safe gathering and urging people to show some safety concern for the coronavirus measures.” Police had asked RAC to postpone the protest, which is expected to attract some 150 to 200 people. But the group’s lawyer, Emmanuel Kerkyasharian SC, told the court the protest was a matter of urgency given that refugees were being held in custody against their will. He also argued that the rally was no different to gatherings that were allowed in schools, airports and parliament. Supple said RAC did not intend to take the case to the court of appeal and would instead push ahead with the protest.