Friends and family of a critically ill man who has lived in Britain since arriving in 1960 aged three have called on the government to apologise for his treatment and fast-track compensation after he spent weeks in intensive care fighting a Home Office decision to refuse him citizenship.

Hubert Howard, 62, was finally granted British citizenship a fortnight ago, after his lawyer highlighted the seriousness of his illness. His family say the stress caused by his protracted battle with the Home Office has contributed to his ill health. He remains seriously ill in hospital, and they say the U-turn on his citizenship has come too late.

His lawyer, Connie Sozi, who had to gather material for legal action during interviews with Howard in hospital, said she was dismayed by the “overall injustice” of the case and the Home Office’s systemic failure to help him resolve his documentation issues which led to him being sacked from his job in 2012, prevented him from visiting his dying mother in Jamaica, and pushed him thousands of pounds into debt.

After the government apologised for the Windrush mistakes last year, Howard had hoped to travel to Jamaica, but the ongoing dispute about his right to citizenship made it impossible.

“My client’s life has disintegrated as a result of the uncertainty over his immigration status,” Sozi said. “Had he received confirmation of his status earlier, he would have gone to see his mother, not lost his job and not faced such a traumatising last few years.”

His daughter, Maresha Howard, said the Home Office’s failure to acknowledge that her father was in the UK legally had put him under enormous pressure. “He has gone into debt. He wasn’t able to get a bank account. He has tried hard to sort it out, but it has made him sick. As a family we have seen him very ill and struggling.”

She said her father had felt distressed to have been granted citizenship as an apparent concession to his ill-health. He has leukaemia and a chest infection. “To get it out of pity after being ill in intensive care, it feels humiliating. He feels stripped of his dignity. He needs an apology and compensation,” she said.

Tyrone McGibbon, a lifelong friend who met Howard when they were schoolchildren, said: “This has been killing him. It has had a massive effect on his physical state and the stress of constantly fighting the Home Office just to prove his status has ruined him. It has really hurt me as a friend to see the way he has been treated.”

He added: “Theresa May said there would be compensation but I haven’t seen anyone get anything. How many more people have to die before they do something about this? He wanted to go to Jamaica, but I’m not sure now that he will have a chance to travel.”

Last month Jashwa Moses, a reggae musician who arrived in Britain in the 1960s aged 12, died shortly after securing citizenship, too late to travel back to Jamaica. Sarah O’Connor and the former Middlesex bowler Richard Stewart both died before receiving compensation or personal apologies from the government. Both their families said they had become stressed and depressed by the process of attempting to prove how the Home Office’s mistakes had caused them decades of difficulties. There is concern at the slowness of the compensation scheme which was launched in March.

Howard, who has not left the country since 1960, first realised he had problems with his documents in 2005 when his employers, Peabody, asked for evidence that he was in the UK legally. He tried to get a passport the following year so he could visit his mother in Jamaica; the Home Office told him they had no record of him and consequently he was unable to travel. He tried repeatedly to contact the Home Office to arrange a passport. In 2012 he was sacked by Peabody because he was still unable to prove he was in the UK legally. He thinks he made more than 50 phone calls to the Home Office, fruitlessly attempting to resolve this issue over 13 years.

“I don’t see how an organisation calling itself the Home Office can treat people like this. I don’t understand how the government can treat people like this,” Howard told the Guardian last year. “It has completely ruined my life.”

He was earning £23,500 a year when he lost his job, and had hoped that a compensation payment would reflect that he was wrongly denied the chance to work for six years.

Although his right to be in the UK was formally recognised by the Home Office after the Windrush scandal emerged last year, an application for British citizenship was rejected a few months later, because he failed the good character requirement, as a result of a suspended sentence he received for common assault last year. He had pleaded not guilty to the offence, which related to a dispute he had at a doctor’s surgery when he was trying to get a form signed to prevent disability benefits being removed. His lawyer said it was alleged that he grabbed paperwork from the receptionist’s hand, and grabbed her finger, causing her pain, and then threw the form at her. Sozi said her client was distressed because of a misunderstanding over a form he urgently needed to submit, which he had been chasing for days.

Howard was dismayed that he been denied citizenship as a result of a minor incident. A reference written last year by his former employers, Peabody, highlighted his good character. “I can confirm that Hubert has great integrity, is a passionate and loyal person and has a warm and friendly disposition,” said the letter. “He was well-respected by both residents and his colleagues. He was reliable, hardworking and diligent in his duties.”

Before he was admitted to hospital in August, Howard said he was devastated by the ongoing difficulties with resolving his status and compensation claim. “We all feel the stress. I’ve been knocking my head against a brick wall for years. It makes me feel like I am crazy. I’ve been here since I was 1960. It’s not like I’m a dangerous person. I feel I can’t take any more.”

A Home Office spokesperson said: “We have been resolute in our determination to right the wrongs experienced by the Windrush generation. Mr Howard has been granted citizenship by the Windrush taskforce. The Windrush compensation scheme aims to provide a decision to applicants as soon as they are able but it is right that we take the time to ensure these are dealt with properly.”