Around 80 migrants held at Harmondsworth immigration removal centre have produced a dossier alleging serious mistreatment by the Home Office, demanding an investigation by the UN.
The detainees, who arrived in Britain via small boat crossings and now face deportation to France under Labour's "one in, one out" policy, claim they have suffered severe psychological harm at the facility near Heathrow Airport.
The group, which includes individuals from Afghanistan, Sudan and Iran, claim they travelled to Britain seeking a "peaceful life" but allege their treatment breaches human rights principles around dignity and due process.
According to the document, detainees were hurried into the removal centre immediately after their Channel crossings without adequate time to recover or receive support, and were prevented from reaching their families.
Around 80 migrants held at Harmondsworth immigration removal centre have produced a dossier alleging serious mistreatment
|GETTY
The migrants allege medical treatment has been withheld for various health conditions they report experiencing, while many suffer from depression, anxiety and sleeplessness.
"There have been multiple incidents involving individuals experiencing severe mental health crises, including self-harm attempts," the document reads.
"Detainees report being placed in isolation or disciplinary units.
"This environment has created constant fear, despair, and uncertainty, with detainees expressing that they feel dehumanised and invisible."
The group is urging the UN and human rights organisations to conduct a formal examination of conditions at detention facilities housing those awaiting removal from Britain.
The group is urging the UN to conduct a formal examination of conditions at the detention facility
|PA
The scheme, agreed between Sir Keir Starmer and Emmanuel Macron last summer, has come under fire after official data revealed Britain has accepted more asylum seekers than it has removed.
Between September and December, just 193 migrants who crossed the Channel in small boats were returned.
The policy has also been undermined by legal challenges and the embarrassing return of two previously deported men who subsequently made their way back on small boats.
The first deportation flight to France this year under the arrangement is scheduled for Wednesday.
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The Home Office has rejected the allegations made by the detainees
| GETTYLast year saw 41,472 migrants cross the Channel, representing a 13 per cent increase on 2024's figure of 36,816 and the second-highest total recorded.
The Home Office has rejected the allegations made by the detainees, with a source saying that asylum seekers are informed of their entitlement to legal representation within 24 hours of arriving at an immigration removal centre.
Detainees are provided with free legal advice sessions and can access a 30-minute initial consultation to connect with legal providers for further assistance, the source added.
The department maintains that all those held are given mobile phones and may use landline or video calling facilities to contact relatives and friends, with five minutes of free international calls available.
The source said detainees have access to 24-hour medical staff, mental health support, dental care and treatment for substance misuse.
A spokesman for the Home Office said: "We do not recognise the claims relating to conditions at Harmondsworth.
"We regard the welfare of people detained in our care as being of utmost importance.
"Protecting the UK border is our top priority. Our landmark one-in-one-out scheme means we can now send those who arrive on small boats straight back to France - striking at the heart of the criminal gangs' business model."
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