Suella Braverman, the home secretary, is being urged by 44 leading charities to launch a Windrush-style inquiry into the crisis that engulfed Manston processing centre. Organisations including the Refugee Council, Save the Children and the International Rescue Committee have written a letter to the Guardian seeking an independent investigation into how people seeking refuge in the UK were forced to live in cramped and insanitary conditions. The UK’s reputation has been tarnished by the “appalling” way in which people seeking asylum were treated at the Kent centre amid reports of infectious diseases not being contained, they claim. They call for a review, similar to the inquiry conducted by Wendy Williams into the Windrush scandal, which focuses on lessons to be learned by the department to ensure that it never happens again. “It seems clear that there have been serious failings which have put the health and wellbeing of many people – from those seeking asylum to Home Office staff and others – at risk. “The home secretary should now initiate an independent inquiry into what happened at Manston and the wider handling of this issue. Like the independent Windrush review it must focus on identifying the key lessons for the Home Office going forward,” the letter says. By the end of October, there were more than 4,000 people being held at Manston, a facility designed to hold no more than 1,600, while unconfirmed reports emerged of outbreaks of infectious diseases. Many of those held there had recently travelled across the Channel by small boat and were held for several weeks, in facilities which were only supposed to hold people for 24 hours. A man who died after being held for almost a week at Manston, potentially unlawfully, had contracted diphtheria. This weekend, it emerged that 50 people connected to Manston had contracted the potentially fatal disease. Any investigation could examine why the Home Office failed to book sufficient hotels for the new arrivals, leading to the backlog of people held at Manston. It may also examine the statements from the Home Office about the diphtheria outbreak. The immigration minister, Robert Jenrick, in early November dismissed reports of infections at Manston as “exaggerated”, insisting there were only four diphtheria cases which were being treated appropriately. After the man’s death was announced on 19 November, the department said here was “no evidence at this stage” that he had died from an infectious disease. A week later, the Home Office said he may have died from diphtheria. An inquiry may also examine the legal advice received by Braverman. Jenrick has declined to say whether the department has received advice that it will have to pay compensation to people who were detained in Manston. Williams, an independent expert, was appointed in 2018 to investigate the causes of the Windrush scandal, under which the UK government erroneously classified thousands of legal residents, many of whom arrived from Caribbean countries as children in the 1950s and 60s, as immigrants living in the UK illegally. Her 2020 report contained 30 recommendations for Home Office improvements. Only eight of the 30 recommendations had been fully acted on two years on, Williams said in March. Reacting to the letter, a Home Office spokesperson said: “We work closely with the NHS and UKHSA to support individuals affected by infection and limit transmission, as well as ensure information is shared in a timely way and that everyone leaving facilities such as Manston is given access to appropriate treatment. “The Home Office provides 24/7 health facilities at Manston as well as having robust contingency plans to deal with health issues such as communicable diseases.”