Two Windrush sisters who describe themselves as inseparable are celebrating after a judge ruled that one of them should not be sent back to Nigeria.

Bumi Thomas, 36, was at risk of removal from the UK and at one point was given 14 days to leave, while her sister Kemi, 38, was not because of their different dates of birth.

Bumi took her case to an immigration tribunal hearing last week, and a judge ruled on Wednesday that her removal was not in the public interest.

“I am of the view that the appellant’s life is in this country where she has made a valuable contribution,” the judge said.

Bumi shares a flat with Kemi in south-east London and is a prominent singer on the UK jazz scene.

Kemi was born in December 1981 and qualified for British citizenship as a child born in the UK to parents from a former British colony. Bumi was born in June 1983, just a few months after the introduction of the British Nationality Act. This stipulated that a person born in the UK on or after 1 January of that year became a British citizen automatically only if one of their parents was settled, held indefinite leave to remain or right of abode or was British at the time of their birth.

The family’s roots are in Nigeria. The sisters’ grandfather arrived in the UK from Nigeria in the 1950s to work and study. Their parents, Lizzy and Segun Thomas, settled in Glasgow in 1974 and Kemi and Bumi were born there.

Lizzy and Segun set up the first black hairdressing salon in the area, called Hairlinks. It became a social and cultural hub for Commonwealth citizens. Kemi and Bumi’s parents moved back to Nigeria with their children when Bumi was three. Bumi returned to the UK when she was 18.

Q&A What is the Windrush deportation crisis? Show Hide Who are the Windrush generation? They are people who arrived in the UK after the second world war from Caribbean countries at the invitation of the British government. The first group arrived on the ship MV Empire Windrush in June 1948. What happened to them? An estimated 50,000 people faced the risk of deportation if they had never formalised their residency status and did not have the required documentation to prove it. Why now? It stems from a policy, set out by Theresa May when she was home secretary, to make the UK 'a really hostile environment for illegal immigrants'. It requires employers, NHS staff, private landlords and other bodies to demand evidence of people’s citizenship or immigration status. Why do they not have the correct paperwork and status? Some children, often travelling on their parents’ passports, were never formally naturalised and many moved to the UK before the countries in which they were born became independent, so they assumed they were British. In some cases, they did not apply for passports. The Home Office did not keep a record of people entering the country and granted leave to remain, which was conferred on anyone living continuously in the country since before 1 January 1973. What did the government try and do to resolve the problem? A Home Office team was set up to ensure Commonwealth-born long-term UK residents would no longer find themselves classified as being in the UK illegally. But a month after one minister promised the cases would be resolved within two weeks, many remained destitute. In November 2018 home secretary Sajid Javid revealed that at least 11 Britons who had been wrongly deported had died. In April 2019 the government agreed to pay up to £200m in compensation. Photograph: Douglas Miller/Hulton Archive

It was not until 2009, when Bumi wanted to travel abroad for a holiday and could not get a British passport, that she realised there was a problem. After various battles with the Home Office, she was granted two periods of discretionary leave to remain.

Last November she applied for settlement in the UK. She had had a British partner but her relationship with him ended. The Home Office rejected her application in June and told her she no longer had the right to remain in the UK as she no longer has a British partner.

Bumi’s appeal hearing last week was told that she had left her British partner. Had she remained in that relationship, she may have been granted the right to remain in the UK.

During the hearing Bumi, told the judge: “This is my life, this is my home, this is my country.”

Kemi said: “Bumi is my biggest source of happiness and joy. I can’t imagine what it would be like to have a life where she’s not in it.”

Bumi said on Wednesday: “Kemi and I are both so happy about this decision. I’m laughing then crying then laughing again. Now I can begin to plan my future.”

Bumi’s solicitor, Jamie Bell, from Duncan Lewis solicitors, said: “We are so happy that Bumi’s exceptional life and contribution to the United Kingdom has been acknowledged in the appeal determination. As the judge acknowledged, Bumi’s music has impacted and inspired a large section of the community and we are delighted that she will be able to continue her work in peace.”

Steve Valdez-Symonds, the refugee and migrant rights programme director at Amnesty International, said: “One matter emphasised by Bumi Thomas’s case is how crucially important it is to promote better understanding of British nationality law. Many people still do not know that merely being born in the UK does not in itself make someone a British citizen, and many children grow up in this country without its citizenship – even when the law makes clear they are entitled to register as British.”