A group of asylum seekers due to be flown out of the UK this week in a Home Office operation targeting people who arrived on small boats have launched a mass legal challenge to their removal, the Guardian has learned. Up to 20 people are due to be removed on the charter flight on Wednesday, the first since the coronavirus lockdown to specifically target asylum seekers who have crossed the Channel from mainland Europe by small boats or other clandestine means. At least 17 asylum seekers facing removal have been preparing legal action to prevent them being put on the flight, although it is understood the Home Office has already deferred the removal directions for at least five people initially scheduled to be on it. The asylum seekers lodged pre-action protocols on Monday, the first stage in the judicial review process, to try to halt the Home Office action to remove them. Those involved in the legal action come from countries including Afghanistan, Iran, Kuwait and Yemen and almost all are known to have travelled to the UK in small boats. Some are survivors of torture and some have serious mental health problems as a result of the persecution they have endured in their home countries and on their hazardous journeys in search of safety. The Guardian spoke to one 24-year-old asylum seeker from Yemen who was expecting to be put on Wednesday’s flight but has had his removal directions deferred. He said he had been deeply traumatised by the conflict in Yemen and had crossed deserts on his journey to reach the UK. He has been on suicide watch since being arrested by the Home Office and detained on 30 July. He said he had spent just a few weeks in Calais before paying a smuggler about £700 for a place on a boat that carried 17 people across the Channel. “The smugglers were very aggressive, kicked us and told us to hurry up as we went through the area called the Jungle to get on the boat. They took our belongings off us before we got on the boat. I was very relieved when I reached the UK and felt I was safe at last. But then I got detained.” He said he was so distraught about being detained that he has refused food for several days. He is being monitored round the clock by detention centre staff because of his mental health and trauma problems. Toufique Hossain of Duncan Lewis solicitors, which is challenging many of the forced removals planned for Wednesday, said: “All the clients we represent have strong claims for international protection. They are, by definition, refugees. They also have very strong reasons as to why their claims ought to be processed in the UK. “Rather than vilifying refugees who enter the UK, plotting potentially unlawful ways in which to push them back, [the home secretary] Priti Patel ought to spend time developing safe and durable routes for refugees to claim asylum.” Celia Clarke, the director of the charity Bail for Immigration Detainees, said: “We fear that this cavalier move is part of a strategy to rush through as many removals as possible under Dublin regulations which will cease to be part of UK law after the Brexit date. This is incredibly risky and flies in the face of last week’s health advice from government which was that we had probably ‘reached the limit’ of opening up society.” A Home Office spokesperson said: “We want to see migrants who have illegally and dangerously crossed the Channel returned to mainland Europe. “While we are unable to comment on ongoing legal proceedings, it is the case that the current legal framework is often abused by activist lawyers to frustrate the government’s attempts in this regard.”