A government plan to stop people-smugglers from using social media to advertise small boat crossings across the Channel could result in lawful footage being censored, campaign groups have warned. Michelle Donelan, the culture secretary, said on Tuesday that she would use the online safety bill to ensure social media companies proactively tackle “TikTok traffickers” or risk fines of up to 10% of turnover, as imposed by Ofcom. But a refugee charity and a free speech campaign group have warned that it could force tech firms to take down legitimate material that highlights the plight of people seeking refuge in the UK. Under the proposed amendment, aiding and abetting immigration offences by posting videos of people crossing the Channel – and which show that activity in a “positive light” – could constitute an online offence and would therefore need to be taken down by social media platforms. Open Rights Group, which campaigns for privacy and free speech online, said the change could force social media companies into overzealous policing of their platforms. This could include taking down lawful posts with automated systems based on “perceptual hashing”, which effectively compares posts taken from social media feeds against a database of images. “The chances are they would rely on artificial intelligence techniques, or content moderation systems based on perceptual hashing,” said Dr Monica Horten, a policy manager at ORG. “Both options entail risks of over-blocking. Lawful posts could be censored, with serious implications for public discourse in the UK.” Clare Moseley, the founder of the charity Care4Calais, which cares for refugees crossing the Channel, said: “The controversial question of Channel crossings is a matter of life and death for the vulnerable people that we represent. Our country’s response should be a matter of open and honest debate. If this bill limits our ability to highlight the plight of refugees, it not only threatens their rights but sets a worrying precedent for campaigners.” TikTok has said it already “proactively removes” content from people-smugglers that promotes Channel crossings. Bridget Chapman, a Kent-based activist who has worked with people who have crossed the Channel, said banning social media posts would not stop crossings. “Nobody is making this journey because of a TikTok video. We could close down these routes overnight if the government gave people a safer means of getting here.” A Home Office spokesperson said the amendment, which the government plans to lay down in the Lords, would have no impact on humanitarian or journalistic posts about illegal immigration and did not technically constitute a new criminal offence. They said: “Posts promoting illegal routes to the UK are putting vulnerable people’s lives at risk and funding vile criminal gangs. We are adding illegal immigration offences which already exist in UK law to the list of priority offences in the bill. “This means tech firms will have to take proactive steps to stop people-smugglers from carrying out their business on social media and remove content that seeks to aid, abet or encourage people to commit an existing immigration offence.”