A man caring for his terminally ill partner has been told he faces deportation from the UK to Jamaica because the Home Office concluded that he “failed to demonstrate that his life would be at risk in Iraq”.

O’Neil Wallfall, 49 – who has never been to Iraq – received a refusal letter that appeared to indicate his case had been confused with someone else’s. The government also said it would not be “unreasonable” or “unduly harsh” to expect his British partner, 56-year-old Karen McQueen, to relocate to Jamaica with him.

McQueen has a diagnosis of terminal cancer and is awaiting a transplant after kidney failure.

In the letter rejecting Wallfall’s application – which his lawyer said provided clear evidence that the government “copies and pastes” letters and disregards individual submissions when reaching its conclusions – the Home Office says: “You have claimed that you will be unlawfully killed on return to Iraq … you have not demonstrated … that death is virtually certain.”

After being contacted by the Guardian the Home Office said it was reconsidering its decision “in light of further information”.

Wallfall has been in the UK since 2002 and has been in a relationship with McQueen for three years. She is dependent on him for support with her serious health conditions, the couple say.

In the letter officials say they do not believe the couple’s relationship is genuine because Wallfall’s name is not with McQueen’s on the tenancy agreement. However, under the Home Office’s so-called hostile environment rules those without the right to reside in the UK have no right to rent property.

Officials say they do not accept it would be “unreasonable” or “unduly harsh” to expect McQueen to relocate to Jamaica with him. They say she can get medical treatment there. Officials conclude there are no compassionate factors in this case as the relationship is not a genuine one.

Wallfall said: “The Home Office should not have made the mistake of saying I’m from Iraq. How could they have considered my case properly if they wrote things like that in the refusal letter?

“I believe that my life will be at risk from gangs if I’m sent back to Jamaica. My case should have been considered properly without cut-and-paste information about Iraq in it. The Home Office has treated me so unfairly. They locked me up in detention for many months. My mum died while I was locked up and I was taken to her funeral by immigration officers.”

He said he was angry that the Home Office had decided his relationship with McQueen was not genuine.

“I would love the Home Office to move in here for two weeks and see how we cook together, do everything together and share a bed,” he said. “This is no fake relationship. I’m a clean churchgoing man trying to live a good life. I have been through so much because of the Home Office. When people see me in the street they are seeing a ghost.”

McQueen said she was distraught about the Home Office’s decision.

“O’Neil is a good man and he could contribute so much to our society if he was allowed to,” she said. “I can’t believe the Home Office refused his case because they said he couldn’t prove he would be in danger in Iraq.

“Going through all of this with O’Neil has made me feel as if I’m under the control of immigration myself. O’Neil is a loving, caring and supportive partner. Being with him and having his help and support has given me a new lease of life despite my terminal illness.”

Wallfall’s solicitor, Naga Kandiah of MTC Solicitors, condemned the quality of the Home Office’s refusal letter. He has lodged an appeal and also sent a pre-action letter before starting judicial review proceedings against the Home Office.

Kandiah expressed concern that the Home Office backdated the refusal letter – so that Kandiah would not be able to lodge an appeal within the 14-day deadline. The date on the letter was 3 October 2019 yet the date on the recorded delivery slip when it arrived in Kandiah’s office was 22 October.

Other than saying it was reconsidering its decision, the Home Office did not respond to questions from the Guardian about whether the refusal letter had been deliberately backdated, why references to Iraq were made, why there were not considered to be compassionate grounds in this case and why the relationship was deemed fake because O’Neil’s name was not on the tenancy agreement.

Kandiah said: “The Home Office regularly continues to abuse power and disregard clients’ submissions. There is clear evidence to demonstrate case workers’ copy-and-paste decisions that are backdated. This suggests that they do not train staff properly, exhibit complete lack of quality assurance and waste hours of solicitors’ time and taxpayers money.”