In the summer of 2013, the government launched the peculiarly named Operation Vaken, an initiative that saw vans drive around six London boroughs, carrying billboards that warned: “In the UK illegally? Go home or face arrest.” The billboards were decorated with pictures of handcuffs and the number of recent immigration arrests (“106 arrests last week in your area”). A line at the bottom adopted a softer tone: “We can help you to return home voluntarily without fear of arrest or detention.”

The Conservatives’ 2010 manifesto promise to reduce migration to the tens of thousands had been going badly. It was time for ministers to develop new ways of scaring immigrants into leaving and for the government’s hostile environment policy to get teeth. More than 170,000 people, many of them living in this country legally, began receiving alarming texts, with warnings such as: “Message from the UK Border Agency: you are required to leave the UK as you no longer have the right to remain.”

The hope was that the Home Office could get people to “self-deport”, frightening them into submission. In this, politicians appeared to have popular support: a YouGov poll at the time showed that 47% of the public approved of the “Go home” vans. The same year, Home Office vehicles began to be marked clearly with the words “Immigration Enforcement”, to alert people to the hovering presence of border guards.

Operation Vaken ran for just one month, and its success was limited. A Home Office report later found that only 11 people left the country as a result; it also revealed that, of the 1,561 text messages sent to the government’s tip-off hotline, 1,034 were hoaxes – taking up 17 hours of staff time.

As part of Operation Vaken, vans drove around six London boroughs, carrying billboards that warned: ‘In the UK illegally? Go home or face arrest.’ Photograph: PR

Theresa May’s former adviser Nick Timothy later tried to argue that the vans had been opposed by the prime minister and were only approved while she was on holiday. But others who worked on the project insisted that May had seen the wording on the vans and requested that the language be toughened up. Meanwhile, the Immigration Enforcement vehicles stayed, with their yellow fluorescent stripes and black-and-white checks, a sinister presence circling areas of high migration. Gradually, the broader strategy of intimidation began to pay off. Some people were frightened into leaving.

In my two years of reporting on what became known as the Windrush scandal, Joycelyn John’s experience was the most disturbing case I came across. Joycelyn arrived in London in 1963 at the age of four, travelling with her mother on a Grenadian passport as a British subject. She went to primary and secondary school in Hammersmith, west London, before working in hotels in the capital – including the Ritz and a Hilton.

Some time around 2009, she lost her Grenadian passport, which contained the crucial stamp giving her indefinite leave to remain. She had trouble getting a new passport, because her mother had married and changed her daughter’s surname from Mitchell to John. Because she never registered the change, there was a discrepancy between Joycelyn’s birth certificate and the name she had used all her adult life. She spent several years attempting to sort out her papers, but by 2014, aged 55, she had been classified as living in Britain illegally. She lost her job and was unable to find new work. For a while, she lived in a homeless hostel, but she lost her bed, because the government does not normally fund places for people classified as illegal immigrants. She spent two years staying with relatives, sleeping on sofas or the floor.

The idea of being forcibly taken away terrified Joycelyn. 'There’s such stigma... I didn’t want to be in handcuffs'

In that time, Joycelyn managed to gather 75 pages of evidence proving that she had spent a lifetime in the UK: bank statements, dentists’ records, medical files, tax records, letters from her primary school, letters from friends and family. But, inexplicably, this was not enough. Every letter she received from the Home Office warned her that she was liable to be deported to Grenada, a country she had left more than 50 years ago. She began to feel nervous about opening the door in case immigration officers were outside.

A Home Office leaflet encouraging people to opt for a voluntary departure, illustrated with cheerful, brightly coloured planes and published about the same time as the “Go Home” vans were launched, said: “We know that many people living in the UK illegally want to go home, but feel scared of approaching the Home Office directly. They may fear being arrested and detained. For those returning voluntarily, there are these key benefits: they avoid being arrested and having to live in detention until a travel document can be obtained; they can leave the UK in a more dignified manner than if their removal is enforced.” This appeal to the desire for a dignified departure was a shrewd tactic; the idea of being forcibly taken away terrified Joycelyn, who saw the leaflets and knew of the vans. “There’s such stigma... I didn’t want to be taken off the plane in handcuffs,” she says. She was getting deeper into debt, borrowing money from a younger brother, and felt it was no longer fair to rely on him.

When the hostile environment policy is working well, it exhausts people into submission. It piles up humiliations, stress and fear until people give up. In November 2016, Joycelyn finally decided that a “voluntary” departure would be easier than trying to survive inside the ever-tightening embrace of Home Office hostility. Officials booked her on a flight on Christmas Day; when she asked if she could spend a last Christmas with her brother and five sisters, staff rebooked her for Boxing Day. She was so desperate that she felt this was the best option. “I felt ground down,” she says. “I lost the will to go on fighting.”

Amelia Gentleman in the Guardian office: ‘Readers offered financial support, lawyers offered their services. One reader sent a box of chocolate bars, to keep staff energy levels up’. Photograph: Jill Mead/The Guardian

By that point, she estimated she must have attempted a dozen times to explain to Home Office staff – over the phone, in person, in writing – that they had made a mistake. “I don’t think they looked at the letters I wrote. I think they had a quota to fill – they needed to deport people.” She found it hard to understand why the government was prepared to pay for her expensive flight, but not to waive the application fee to regularise her status. A final letter told her: “You are a person who is liable to be detained... You must report with your baggage to Gatwick South Virgin Atlantic Airways check-in desk.” The letter resorted to the favoured Home Office technique of scaring people with capital letters, reminding her that in her last few weeks: “YOU MAY NOT ENTER EMPLOYMENT, PAID OR UNPAID, OR ENGAGE IN ANY BUSINESS OR PROFESSION.” It also informed her that her baggage allowance, after a lifetime in the UK, was 20kg – “and you will be expected to pay for any excess”.

How do you pack for a journey to a country you left as a four-year-old? “I was on autopilot,” Joycelyn recalls. “I was feeling depressed, lonely and suicidal. I wasn’t able to think straight; at times, I was hysterical. I packed the morning I left, very last-minute. I’d been expecting a reprieve. I didn’t take a lot – just jeans and a few T-shirts, a toothbrush, some Colgate, a towel – it didn’t even fill the whole suitcase.” She had £60 to start a new life, given to her by an ex-boyfriend. She had decided not to tell her sisters she was going; she confided only in her brother. “I just didn’t want any fuss.” She didn’t expect she would ever be allowed to return to Britain.

In Grenada, she found everything unfamiliar. She had to scrub her clothes by hand and struggled to cook with the local ingredients. “It’s just a completely different lifestyle. The culture is very different.” She was given no money to set her up and found getting work very difficult. “You’re very vulnerable if you’re a foreigner. There’s no support structure and no one wants to employ you. Once they hear an English accent – forget it. They’re suspicious. They think you must be a criminal if you’ve been deported.”

Joycelyn recounts what happened to her in a very matter-of-fact way, only expressing her opinion about the Home Office’s consistent refusal to listen when I ask her to. But her analysis is succinct: “The way I was treated was disgusting.” I still find it hard to accept that the government threatened her until she felt she had no option but to relocate to an unfamiliar country 4,300 miles away. The outcome – a 57-year-old Londoner, jettisoned to an island off the coast of Venezuela, friendless and without money, trying to make a new life for herself – is as absurd as it is tragic.

***

In April 2018, the leaders of 52 countries arrived in London for the Commonwealth heads of government meeting. The Mall was decorated with flags; caterers at Buckingham Palace prepared for tea parties and state dinners. In normal times, this summit would have been regarded as a routine diplomatic event, heavy with ceremony and light on substance. But, with Brexit looming, the occasion was seen as an important opportunity to woo the countries on which Britain expected to become increasingly reliant.

A week before the event, however, the 12 Caribbean high commissioners had gathered to ask the British government to adopt a more compassionate approach to people who had arrived in the UK as children and were never formally naturalised. “I am dismayed that people who gave their all to Britain could be discarded so matter-of-factly,” said Guy Hewitt, the Barbados high commissioner. “Seventy years after Windrush, we are again facing a new wave of hostility.”

Hewitt revealed that a formal request to meet May had been declined. The rebuff convinced the Caribbean leaders that the British government had either failed to appreciate the scale and seriousness of what was happening or, worse, was aware, but did not view it as a priority. It smacked of racism.

Passengers from the Caribbean arrive in Britain on the Begona liner in 1962. Photograph: Topham Picturepoint/Press Association Images

By then, I had been covering cases such as Joycelyn’s for six months. I had written about Paulette Wilson, a 61-year-old grandmother who had been detained by the Home Office twice and threatened with deportation to Jamaica, a country she had left half a century earlier; about Anthony Bryan, who after 50 years in the UK was wrongly detained for five weeks; and about Sylvester Marshall, who was denied the NHS radiotherapy he needed for prostate cancer and told to pay £54,000 for treatment, despite paying taxes here for decades. Yet no one in the government had seemed concerned.

I contacted Downing Street on 15 April to ask if they could explain the refusal to meet the Caribbean delegation. An official called back to confirm that a meeting had not been set up; there would be other opportunities to meet the prime minister and discuss this “important issue”, she said.

It was a huge mistake. An article about the diplomatic snub went on the Guardian’s front page and the political response was instantaneous. Suddenly, ministers who had shown no interest were falling over themselves to express profound sorrow. The brazen speed of the official turnaround was distasteful to watch. Amber Rudd, then the home secretary, spoke in parliament to express her regret. The Home Office would establish a new team to help people gather evidence of their right to be here, she announced; fees would be waived. The prime minister decided that she did, after all, need to schedule a meeting with her Caribbean colleagues.

There were a number of factors that forced this abrupt shift. The campaigner Patrick Vernon, whose parents emigrated from Jamaica in the 50s, had made a critical connection between the scandal and the upcoming 70th anniversary of the arrival of the Empire Windrush at Tilbury Docks. A fortnight earlier, he had launched a petition that triggered a parliamentary debate, calling for an immigration amnesty for those who had arrived as British subjects between 1948 and 1971. For months, I had been describing these people as “Caribbean-born, retirement-age, long-term British residents”, a clunky categorisation that was hard to put in a headline. But Vernon’s petition succinctly called them the “Windrush generation” – a phrase that evoked the emotional response that people feel towards the pioneers of migration who arrived on that ship. Although it was a bit of a misnomer (those affected were the children of the Windrush generation), that branding became incredibly potent.

After months of very little coverage, the BBC and other media outlets began to report on the issue. On 16 April, the Guardian reprinted the photographs and stories of everyone we had interviewed to date. The accounts were undeniable evidence of profound and widespread human suffering. It unleashed political chaos.

***

It was exciting to see the turmoil caused by the relentless publication of articles on a subject that no one had previously wanted to think about. Everyone has moments of existential doubt about whether what they do serves a purpose, but, for two weeks last April, the government was held to account and forced to act, demonstrating the enormous power of journalism to trigger change.

At home it was chaos. I wrote until 2am and got up at 5am. My dictaphone overheated and one of its batteries exploded

At the Guardian’s offices in London, a team of reporters was allocated to interview the huge number of emerging Windrush voices. Politicians were contacted by constituents who had previously been nervous about giving their details to officials; they also belatedly looked through their constituency casebooks to see if there were Windrush people among their immigration caseload; finally, they began to speak up about the huge difficulties individuals were facing as a result of Home Office policy.

Editors put the story on the front page, day after day. Any hope the government might have had of the issue quickly exhausting itself was dashed repeatedly by damaging new revelations. For a while, I was unable to get through my inbox, because there were too many unhappy stories about the government’s cruel, bureaucratic mishandling of cases to be able to read and process. Caroline Bannock, a senior journalist who runs the Guardian’s community team, created a database to collect people’s stories, and made sure that everyone who emailed got an answer, with information on where to go for advice and how to contact the Windrush Taskforce, set up by Rudd.

I found the scale of the misery devastating. One morning, I came into work to find 24 messages on my answerphone from desperate people, each convinced I could help. I wanted to cry at my desk when I opened a letter from the mother of a young woman who had arrived in Britain from Jamaica in 1974, aged one. In 2015, after being classified as an illegal immigrant and sent to Yarl’s Wood detention centre, she had taken an overdose and died. “Without the time she spent in Yarl’s Wood, which we understand was extremely unpleasant, and the threat of deportation, my daughter would be alive today,” she wrote. The government had been aiming to bring down immigration at any cost, she continued. “One of the costs, as far as I am concerned, was my daughter’s life.”

Passengers waiting to disembark from the Empire Windrush, 21 June 1948. Photograph: Daily Herald Archive/Getty Images

Alongside these upsetting calls and letters, there were many from readers offering financial support to the people we interviewed, and from lawyers offering pro bono assistance. A reader sent a shoebox full of chocolate bars, writing that he wanted to help reporters keep their energy levels up. At a time when the reputation of journalism can feel low, it was rewarding to help demonstrate why independent media organisations are so important.

If the scene at the office was a smooth-running model of professionalism, at home it was chaos. I wrote until 2am and got up at 5am to catch up on reading. I tapped out so many articles over two weeks that my right arm began to ache, making it hard to sleep. My dictaphone overheated from overuse and one of its batteries exploded. I had to retreat entirely from family life, to make sure I poured out every bit of information I had. Shoes went missing, homework was left undone, meals were uncooked. There was an unexpected heatwave and I was aware of the arrival of a plague of ants, flies and fleas (and possibly nits), but there was no time to deal with it.

Joycelyn still has nightmares. 'Before this, I felt British. Now I feel I don't belong here – and I don't belong there'

I am married to Jo Johnson, who at the time was a minister in May’s government. As a news reporter, I have to be politically independent; I let him get on with his job and he doesn’t interfere in mine. Life is busy and mostly we focus on the day-to-day issues that come with having two children. Clearly, there are areas of disagreement, but we try to step around anything too contentious for the sake of family harmony.

But the fact did not go unnoticed. One Sunday morning, Jo had to go on television to defend Rudd, returning home at lunchtime to look after the children so I could talk on the radio about how badly the government had got it wrong. I can see why it looks weird from the outside; that weekend it felt very weird. I had only one brief exchange about the issue with his brother Boris, who was then the foreign secretary, at a noisy family birthday party later in the year. He said: “You really fucked the Commonwealth summit.”

***

On 25 April, Rudd appeared in front of the home affairs select committee. She told MPs she had been shocked by the Home Office’s treatment of Paulette and others. Not long into the session, Rudd was thrown off course by a question put to her by the committee’s chair, Yvette Cooper. “Targets for removals. When were they set?”

“We don’t have targets for removals,” she replied with easy confidence. It was an answer that ended her career as home secretary.

In an earlier session, Lucy Moreton, the head of the Immigration Service Union, had explained how the Home Office target to bring net migration below 100,000 a year had triggered challenging objectives; each region had a removal target to meet, she said. Rudd’s denial seemed to indicate either that she was incompetent and unaware of how her own department worked, or that she was being dishonest. Moreton later told me that, as Rudd was giving evidence, colleagues were sending her selfies taken in front of their office targets boards.

Amber Rudd gives evidence to a select committee hearing on 25 April. She resigned four days later, after denying that the Home Office had removal targets. Photograph: PA

Rudd was forced back to parliament the next day. This time, she admitted that the Home Office had set local targets, but insisted: “I have never agreed there should be specific removal targets and I would never support a policy that puts targets ahead of people.” But, on 29 April, the Guardian published a private memo from Rudd to May, sent in early 2017, that revealed she had set an “ambitious but deliverable” target for an increase in enforced deportations. Later that evening, she resigned.

When I heard the news, I felt ambivalent; Rudd hadn’t handled the crisis well, but she wasn’t responsible for the mess. She seemed to be resigning on a technicality, rather than admitting she had been negligent and that her department had behaved atrociously on her watch. The Windrush people I spoke to that night told me Rudd’s departure only shifted attention from the person who was really responsible: Theresa May.

***

Joycelyn John was issued with a plane ticket from Grenada to England in July 2018. “A bit of me was ecstatic, a bit of me was angry that no one had listened to me in the first place,” she told me when we met at her still-bare flat in June this year. She had been rehoused in September, but the flat was outside London, far from her family and empty; council officials didn’t think to provide any furniture. Friends gave her a bed and some chairs, but it was months before she was able to get a fridge.

In late 2018, she received a letter of apology from the then home secretary, Sajid Javid. “People of the Windrush generation who came to Britain from the Commonwealth, as my parents did, have helped make this country what it is today,” he wrote. “The experiences faced by you and others have been completely unacceptable.” The letter made her cry, but not with relief. “I thought: ‘What good is a letter of apology now?’ They ruined my life completely. I came back to nothing. I have had to start rebuilding my life from scratch at the age of 58.”

She still has nightmares that she is back in Grenada. “I can feel the heat, I can smell the food, I can actually taste the fish in the dream – in a good way. But mostly they are bad memories.” The experience has upended her sense of who she is. “Before this I felt British – I just did. I’m the sort of person who would watch every royal wedding on television. I feel less British now. I feel I don’t belong here, and I don’t belong there.”

While a government compensation scheme has been announced, Joycelyn, like most of the Windrush generation, has yet to receive any money. Since the government apologised for its “appalling” treatment, 6,000 people have been given documents confirming their right to live in the UK. Joycelyn is one of them. But, although her right to be here is now official, she hasn’t yet got a passport – because she can’t afford the fee. And she remains frightened. “I’m still looking over my shoulder all the time. I’m a nervous wreck.”

• The Windrush Betrayal: Exposing the Hostile Environment by Amelia Gentleman is published by Guardian Faber Publishing. To order a copy for £13.99 (RRP £18.99), go to guardianbookshop.com. Free UK P&P on all online orders over £15.

Amelia Gentleman will talk about the Windrush Betrayal at a Guardian Live event in London on Wednesday 16 October.

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