The Home Office’s refusal to renew the UK passports of a Black British former servicewoman and her husband had “devastating” consequences over decades, years after Enoch Powell’s NHS recruitment drive brought their mothers to Britain.

Hetticia and Vanderbilt McIntosh had their UK status revoked in the 1970s and 1980s, through no fault of their own. The married parents of three were forced to start again in St Lucia, more than 4,000 miles away.

The Home Office only gave the couple new British passports in 2020 – after news emerged of the Windrush scandal, which involved the wrongful deportation and denial of rights to Black, Caribbean and African-born Britons living legally in the UK over decades.

Despite the significant disruption to their family life, NHS care and pensions, the McIntoshes were each refused compensation from the Windrush compensation scheme three times between 2021 and this year.

In 2019, Windrush scandal survivors were told there would be “no cap” on payments. Instead, the scheme has been plagued by knockbacks, delays and desultory offers.

Hetticia was eventually offered £40,000 this year after Southwark Law Centre, a registered charity, took on her case. However, Vanderbilt has received a “nil offer”. Even though the Home Office has admitted its error by giving him his British passport back, officials say he does not qualify for compensation because he entered the country as a “visitor” in 1993 – the only way he could at the time.

In April, the government launched the £1.5m Windrush compensation advocacy support scheme to “provide claimants with dedicated advocates from community organisations” to support applications.

But Hetticia’s experience has convinced her that only expert lawyers can tackle the system. She has refused her compensation offer and started a change.org petition for legal aid for Windrush scandal survivors, which has been signed by nearly 20,000 people. She has also been lobbying politicians in the Caribbean to raise awareness. Research this year revealed claimants received huge increases in compensation offers – in one case jumping from £300 to £170,000 – after legal advice.

The McIntoshes, who now live in Manchester, first entered the UK as British subjects and small children before obtaining British passports. Hetticia’s mother was a Barbadian nurse employed by Manchester Royal Infirmary as part of an early-1960s NHS recruitment drive by the then Conservative health secretary, Enoch Powell, which primarily targeted Caribbean nurses and Indian doctors. Vanderbilt’s mother was recruited from St Lucia as a midwife for Newham, east London, in the same period, while his father worked for Ford in Dagenham.

Several years later Powell was dismissed from the Tory shadow cabinet after giving his inflammatory 1968 “rivers of blood” speech, which became one of modern British history’s most divisive addresses.

Hetticia’s UK passport expired in 1973 while she was serving as an army physical training instructor, and in 1978 the Home Office said she was not entitled to a new one because her birth country, Barbados, had become independent from Britain. When Vanderbilt’s passport expired in 1984, he was told he no longer qualified because of St Lucia’s independence.

Hetticia was advised to get a Barbadian passport, which UK officials stamped with “right to abode”, but Vanderbilt, whose grandfather was Scottish, was not given any UK immigration status. Suddenly unable to prove he could work legally, he lost his job at Berger Paints, which cost the couple their east London home. Vanderbilt moved the family to St Lucia in 1985, feeling “rejected and forced out”, which, Hetticia said, nearly destroyed their marriage and forced them to travel back and forth for decades.

The couple’s frustration at their ordeal is compounded by its inconsistencies – their parents and siblings kept their status, while their own children, as British-born citizens, were able to return to the UK to study and work in the mid-1990s.

Hetticia said: “You feel devastated because one day you don’t know who you are any more. We were born British, how is it that was taken away from us?

“The Home Office’s behaviour is very insidious and further traumatising us. They pretend they’re helping you, but they’re not. What they’ve offered me is an insult. There are [Windrush scandal survivors] who are homeless, suffering from dementia, or paralysed with fear. They need legal help. This is not about compensation – it’s about justice.”

About 18,000 people have been given new documents confirming their status or British citizenship since the scandal broke.

A Home Office spokesperson said the home secretary, Yvette Cooper, was “determined to put right the appalling injustices caused by the Windrush scandal”, make sure people received the compensation they rightly deserved and ensure permanent “cultural change” at the department.