Hundreds of migrants were illegally detained in immigration removal centres, according to Home Office emails obtained by JEE News.
The detention centers were used to hold about 450 people – described in one email as “overflow” from the migrant processing facility in Manston.
The email said their detention was “no longer legal”, adding: “We need to move them to hotels ASAP.”
The Home Office said the unusual number of small boat arrivals had put “tremendous pressure” on the asylum system.
It said it had “worked tirelessly to move people to hotels or other accommodation as soon as possible”.
The email was sent on November 4, the day Home Secretary Sylla Braverman visited Manchester in a push to get a grip on overcrowding at the site.
According to a series of emails obtained under the Freedom of Information Act, Home Office permanent secretaries – the department’s most senior civil servants – were briefed on the concerns at the time.
Shadow Home Secretary Yvette Cooper said the emails “show the Home Office knew they were breaking the law and show how their failure to plan led to this situation. “.
“Under [Ms Braverman’s] direction the Home Office has lost control of the system and created potentially substantial legal costs for the taxpayer.”
In October, it was revealed that around 4,000 people were housed in tents in Manchester, causing overcrowding and disease.
By early November, between 450 and 500 asylum seekers had been transferred to immigration removal centers as “Manston ‘overflow'”, according to Home Office emails.
“Their detention is no longer legal as they can only be detained when their identity is closed and then for a maximum of 5 days”.
“Most have been there for several weeks, longer than some of the Manston cases. We need to move them to hotels ASAP…”
Manston was designed to quickly process and release migrants arriving in Britain in small boats.
But inspectors have expressed concern about the number of people “held for long periods in cramped and uncomfortable conditions, often supervised by staff who have not been properly trained”.
The Home Secretary is due to be questioned by a House of Lords committee on Wednesday about asylum accommodation and the backlog of unprocessed claims.
One man, who was detained in Manston for 24 days, claimed he was assaulted by an officer in what the detainees described as a peaceful protest. Kent Police are investigating the allegations.
JEE News has obtained photos taken by staff at the center which show the man with a bloodied face and swollen nose.
After Home Office staff broke up the protest on 27 October, she said she was choked by an officer, and “used all the strength I had with my arm to strangle me”. .
“When I removed his hands, he pushed me and I fell backwards onto someone else. When I was on the floor, the same officer grabbed my head and used his knee to press my head and Broke my nose. From that point, I lost consciousness.”
