Anti-monarchist campaigners have vowed to press ahead with plans to protest peacefully against the coronation of King Charles III on Saturday, despite what they have characterised as intimidatory tactics by the police and the government. The activist group Republic plans to hold a demonstration a short walk from where the king is due to be crowned. They have said they received letters from the Home Office warning them about new powers handed to police to deal with public demonstrations, while Scotland Yard has said its tolerance of protest will be low on the day. “Republic will not be deterred and we will be protesting on Trafalgar Square and along the route of the coronation procession on Saturday,” said the group’s chief executive, Graham Smith. “It is telling that Charles, who has had no problem speaking up on various issues, has chosen not to defend democratic rights when they are being threatened in his name. Perhaps he might make it clear that he believes in the right to protest.” The group said it received communication from the Home Office’s police powers unit that new powers had been brought forward to prevent “disruption at major sporting and cultural events”. Under those powers, blocking roads, airports and railways could bring prison sentences of 12 months, while people locking on to others, objects or buildings could go to prison for six months and face an unlimited fine. Police have also been empowered to stop and search people if they suspect they are setting out to cause disruption by protesting. “We have had two meetings with the Met police, and numerous phone conversations. They have repeatedly said they have no concerns about Republic’s plans. It is a mystery why the Home Office thought it was necessary to send us an anonymous letter that could be interpreted as intimidation,” Smith said. Referring to planned protests in general – not Republic’s demonstration specifically – the Met has said: “Our tolerance for any disruption, whether through protest or otherwise, will be low. We will deal robustly with anyone intent on undermining this celebration.” His group plans to meet on Saturday morning to hold a demonstration in Trafalgar Square. Organisers intend to hand out placards and are encouraging attenders to wear yellow. They are also setting up smaller teams who will stage protests along the procession route. Asked about its plans for the day, the climate crisis campaign group Just Stop Oil said: “While everyone is focused on a billionaire in a shiny hat, the government is signing off on plans to destroy the lives of millions of ordinary people, while enacting laws to ensure that no one can stop them. “They are closing all avenues for dissent and restricting our legitimate rights to protest. But we will not die quietly. We will continue to do whatever is nonviolently possible to end new oil and gas.”