A black community activist has accused police of discrimination after he was threatened with arrest and prosecution for organising an upcoming anti-racism protest march in London. Ken Hinds has launched a legal challenge against the Metropolitan police after the force told him he was not qualified to call a demonstration under coronavirus health protection regulations because he was not “a business, a charitable, benevolent or philanthropic institution, a public body, or a political body. What this means is that you are encouraging anyone attending to commit an offence contrary to [Health Protection] regulations 5 and 8,” said a trainee commander in an email to Hinds last Thursday. The email told Hinds he could also be investigated for offences under the Serious Crime Act “relating to encouraging or assisting the commission of an offence”, simply by organising the demonstration on 30 August. “You may have already committed an offence under the 2007 act by promoting the event,” it said. Hinds is one of a number of campaigners who had called for people to gather in Notting Hill on Sunday, the first day of the west London district’s eponymous carnival, which is cancelled this year. He told the Guardian the Million People March was intended to revive the original spirit of the carnival, which began as an attempt to resolve racial tensions in the capital. “It is to tackle systemic racism – institutional racism – and it’s simply to address that, because all too often we are having inquiries and commissions that are saying the same thing but are seldom followed through … there is no change,” Hinds said. “But what we are trying to say here is that this time it’s different. For the first time we’ve got a significant amount of white people supporting a black cause and joining up and calling for change. That’s a beautiful spirit.” Hinds was threatened with arrest after he asked the Met to help facilitate the peaceful protest. Lochlinn Parker, of ITN solicitors, who is representing Hinds, said: “My client is baffled by the Met police’s approach. It seems to be more than a coincidence that it’s happening on the weekend when the Notting Hill carnival was due to take place.” On Tuesday, Parker delivered to Scotland Yard a letter before action, the first stage of a judicial review. It pointed out that Communities Against Violence, a registered community interest company set up by Hinds and others, which is organising the protest, was focused on changing the law around racism – an explicitly political goal. The letter also pointed out that while the black-led organisation had been threatened with arrest, no white-led protests had faced the same threats in the past month, a disparity it alleged was discriminatory. Police have begun to crack down on events that break coronavirus regulations after the closure of nightclubs led to a series of illegal raves around the country. From Friday, those facilitating or organising any unlawful gatherings of 30 people or more – including protests – may face a £10,000 fine. Kevin Blowe, the coordinator of Netpol, which monitors policing, said he was looking out for instances of the police using the new measure to crack down on protests. “In this particular instance it’s because it is associated with carnival, and they have convinced themselves that it’s basically an alternative to carnival. That’s the alarming thing, the alarming factor of the police deciding what is or isn’t an article 11 [right to] protest.”