In my previous life I worked as a UBS trader, took responsibility for a £1.4bn trading loss in 2011, and served a three-and-a-half year sentence in four different prisons including Maidstone, a foreign national jail.

But not even there was the atmosphere as dystopian as Harmondsworth immigration removal centre where I was moved to prior to my release.

In prison there is an opportunity for progression, a sense of purpose, an end goal, a timeframe for release and even a true sense of community. Although they don’t do it very well, our prisons focus on rehabilitating people, increasing their skills and preparing them to return to society as productive citizens.

Nothing like that happens inside detention centres, even though the majority of detainees end up being released back into the community, as I was this week.

These people are not prisoners and yet they are locked up from 9pm until 8am every day. Yes, unlike prisoners we have mobile phones and can speak to our loved ones, but the stress of navigating unrelenting Home Office efforts to deport us is so damaging to our mental health that our relationships become strained. Our loved ones bear the brunt of our increasing mental fragility. Many relationships don’t survive; I suspect this is one of the key aims of bringing people here. My girlfriend, friends, family and I are having to work extremely hard to ensure this process does not destroy our humanity.

People in detention centres spend all their days in limbo. One week in detention suddenly stretches into a month or three. The men spend their days at the fax machine, in the library, or in the yard chain smoking tobacco roll-ups. They don’t know how long they will be locked up because immigration detention in the UK has no time limit. The sense of hopelessness is etched on every face and strains every conversation.

Some men work behind the servery, in the laundry, or cleaning the corridors. They are paid £1 an hour. Paradoxically this is one place where slave wages are permitted, while, according to Home Office rules, most would not be allowed to work if they were released. Detention feels like a betrayal of our social contract and the basic life rule that if we pay our dues to our community, our place in that community will be protected.

Pressure is rising. In the last few days I was inside, a few incidents took place in the dining hall. The food is tasteless and unvaried: rice, chicken, curry, sausages, chips, zero seasoning. Detainees serve the food on plates made of Styrofoam so that they can’t be used as weapons. At the latest blow-up, the officers formed a wall around the guy who had become agitated. A dining room of 100 hushed men looked on as, this time, the staff struck the right balance and de-escalated the situation so he wouldn’t be sent to the “punishment block”.

I have utter disdain for this environment, an emotion I have not experienced before; not even in prison

Many of the staff members do understand the inhumanity of what is happening and believe their role is to help the men. The vast majority of them are migrants or from minority ethnic communities themselves. Few Caucasians live or work in this environment. Some guards told me this place used to be so much worse. Back in 2002, before emails and mobile phones, there were only fax machines and payphones. Sometimes urgent faxes from detainees were not sent and instead were shoved in a drawer. Payphones used tokens but were not always emptied, rendering the phones out of order and making contact with lawyers and loved ones impossible.

Much of the place is dirty. Recently, the outside cleaners who are brought in to clean the toilets went on strike. The guards tried to recruit detainees to clean them but even the £1.25 an hour “special projects” rate wasn’t enough enticement. On my wing there are five working toilets and showers shared between 60 men; you can imagine the state they are in.

Above each yard is a net that stretches over the entire space to stop people using drones to drop contraband into the detention centre. For 10 days now, the net above yard number three has cradled the slowly decomposing body of a dead pigeon. Every now and then the mice have the courage to scurry across open spaces. Meanwhile, the walls of the yard are adorned with murals of international sports icons; a cruel mockery to these men as they are reminded of their loss of status as global citizens.

I have utter disdain for this environment, an emotion I have not experienced before; not even in prison. The pressure on the Home Office to deport ever more humans is so great that excessive risks are being taken to destroy our shared humanity. Driven to achieve an impossible target, Home Office workers embedded in the detention centre are the deliverers of this distress. Calls to meet them – regular and often – fill everyone with dread. No one knows when their moment will come.

One 28-year-old man who had lived in the UK since he was 14, and has British parents and a brother in the UK, was so terrified of being removed that he hid. Centre staff were ordered to search for him; all of them holding the same A4 photo. Like Keystone Cops they asked us: “Have you seen this guy?” We were eventually sent back to our cells and the detention centre was placed on lockdown. Banged up alone, in my cell, my anxiety mounted both for myself, in case I was dragged out and put on the plane, and for the terrified young man.

Eventually he emerged from his hiding place behind a loose wooden panel underneath a bunk bed, believing enough time had elapsed for him to have missed the flight. He was wrong. When he discovered there was still time to force him on to the plane, he placed a razor blade in his mouth to try to prevent removal. The guards took him to the block, removed the blade and took him to the plane in full shackles. The plane waited for him. I suppose at a cost of £5,000 to deport someone on a charter flight, it would be a huge waste of taxpayers’ money to fail to deliver him on to that plane and across the Sahara.

It is time for fundamental change. Detention centres have no place in our global society. We must abolish them. They are destroying our society and crushing our shared humanity.

• Kweku Adoboli is a former UBS trader who was sent to prison for fraud. He was freed in August 2018 after spending 36 days in a detention centre





