Civil liberty experts have warned that peaceful protest is under threat in the UK, after the environmental campaigners were targeted with pre-emptive arrest and “unworkable restrictions” were placed on this week’s Extinction Rebellion (XR) demonstrations. Thousands of people have taken to the streets this week to highlight the escalating climate emergency and demand urgent action from the government. More than 200 campaigners have so far been arrested. The civil liberties group Liberty said legitimate protest was being hampered by forceful police tactics. “Despite the fact the police have a duty to facilitate protest, recent weeks have seen unworkable restrictions, fines and arrests all used to deter us from exercising our rights,” said Gracie Bradley, the group’s interim director. “These restrictions are heavy-handed and go too far.” The Metropolitan police has issued restrictions under section 14 of the Public Order Act that state the XR demonstration in Westminster must take place within the off-road area of Parliament Square between 8am and 7pm. Protesters said it was an attempt to stifle legitimate protest amid government inaction over the climate emergency. “I think [the police] are a lot more stringent, and much more feisty this time round … It’s very, very different,” said Alice Huntington, a 48-year-old protester from Bedford. “I think it’s disgraceful, it remains to be seen whether this is legal really, but it’s bordering on oppression. We have a legal right to protest, and it feels as though that’s not being allowed.” Roger Lockey, 65, said he felt the police had ramped up their actions for each of the group’s rebellions over the past two years. “The response is much more robust than in October, they are not spending much time allowing us to block roads but we didn’t expect it to be the same,” he said. Last week five climate activists from the newly formed Beyond Politics group were arrested and charged with conspiracy to cause criminal damage. An XR co-founder, Roger Hallam, was among them and he and another activist, Diana Warner, remain in prison on remand. Bradley said: “These tactics are not new but they are damaging as they undermine our right to protest by reframing it as a public nuisance. Peaceful protest is a core pillar of any healthy democracy, and it is vital it is protected whatever the cause.” The Met declined to comment but directed the Guardian to its website where a statement said the restrictions had been imposed as the protest could “result in serious disruption to the life of the community”. This week’s demonstrations are the first mass gathering of XR activists since a rebellion planned for earlier this year was cancelled because of the coronavirus pandemic. The group has been warned it could face a £10,000 fine for organising a gathering of more than 30 people under Covid legislation. In London, XR’s latest rebellion has so far focused on Westminster but activists say they intend to target other institutions responsible for the climate crisis in the days ahead. On Thursday, several protesters in the centre of the capital glued their hands to the pavement in an attempt to block two entrances to parliament, before being removed and arrested by police. Nearby, a group of eight Animal Rebellion demonstrators stopped traffic outside the Department of Health and Social Care, blocking the road with a slaughterhouse truck to raise awareness of the link between animal farming and the climate crisis, as well as the risk of pandemics. “We don’t want to upset people going to work, going about their business, especially with the tough times because of Covid, so we are targeting the main areas of government and organisations we feel are most to blame,” said XR activist Tim Grigg.