A man who has been exiled in Turkey and separated from his British son for more than a year can return home after the UK government conceded it should never have excluded him.

Siyabonga Twala has spent the last 18 months living in limbo in Ankara after he was prevented from boarding a flight back to Manchester with his family in December 2022.

Twala is expected home in Chester within days to be reunited with his nine-year-old son, Mason, after the government revoked a decision to exclude him.

Laughing with relief over the phone from Ankara, Twala said: “I’m so, so happy,” adding that the first thing he wanted to do was play with action figures with Mason. Hours earlier he had been in tears describing the pain of their separation.

The decision was made on Wednesday afternoon, less than 24 hours before a judicial review hearing was due in his case. “It’s surreal, because I was nervous about the hearing tomorrow, so for it to happen now is crazy,” Twala said.

Days before the scheduled hearing it was disclosed to his lawyers that Twala had been on the brink of being brought home by immigration officials more than a year ago but Robert Jenrick, then the immigration minister, had personally intervened to block it. Twala said he had been “a victim of politics”.

The Home Office had decided to allow Twala to return to Britain on the grounds of family life on 23 March last year, court documents show – the same day as the Guardian published a second article on the case. But Jenrick responded a week later to block his return. An exclusion order, normally reserved for terrorists and other serious offenders, was issued in July.

After the Guardian contacted the Home Office for comment on Wednesday about Jenrick’s intervention, the department told Twala’s lawyer that the exclusion order was being withdrawn. Twala will fly home in the next few days, as soon as paperwork confirming the Home Office permission is provided.

His parents, sister and son had just arrived in London on Wednesday afternoon in preparation for the hearing the next day when they were called with the news.

Twala’s father, Siyabonga Twala Sr, said: “I’m ecstatic. I can’t believe it.” He said Mason was “really, really happy” that his father was coming home and he had been “hurt a lot” by the Home Office’s “heartless” treatment of Twala. “I’m so happy for Siyabonga and Mason. This is the best news ever.”

Twala was given indefinite leave to remain in the UK in 2010. The Home Office barred him from re-entering Britain because of a 2018 conviction for cannabis possession with intent to supply. He spent four months in prison for the offence and on his release he retrained and had a steady job as a lorry driver, while looking after Mason at weekends.

Twala said that when he discovered last week that he could have been home for more than a year he was “really, really angry and frustrated”. His mental health has been shattered by the separation from his son.

“I feel like I’ve been a victim of politics,” Twala said. “I’ve missed out on my son because he’s growing up now and I’ve missed out on just being able to be there for him and give him the support that he needs as he transitions into a big boy. He will be turning 10 soon.

“I’ve just felt completely worthless throughout this whole year and financially I’m absolutely ruined.”

Twala, 35, was in transit on his way back from a holiday to South Africa with his family when he was prevented from boarding a flight home at Istanbul airport.

It had been the first time he had returned to the country of his birth since his family moved from Durban to Chester when he was 15. His son, parents and siblings had to return home without him.

Twala, whose younger brother is British, had residency in the UK having grown up in Chester but had not yet got round to applying for citizenship.

An exclusion order carries no right of appeal and is usually reserved for the most serious offenders.

Twala’s lawyer, Nicholas Hughes, said: “While I’m incredibly relieved for him, I’m furious that a political decision has robbed a man and his son of a year and a half of their lives together.”

He said the Home Office’s conduct had been “appalling” and the decision had come less than 24 hours before a hearing “which they knew they would lose”.

Hughes said: “Applying this policy to someone in his circumstances was an unfettered use of discretion and an abuse of power. This is an individual who has a British son, who himself has indefinite leave to remain and has lived in the UK for the majority of his life.”

He noted that Twala’s continued exile had had a “severe” impact on his mental health and that of his son. “It was accepted that he’s not a threat to the UK so it was a severe violation of both his and his son’s right to a private and family life.”

Twala has been unable to work in Ankara. He became homeless last month and has survived on handouts from family and from Guardian readers. Most recently he has been living in a room infested with cockroaches.

Hours before hearing of the Home Office’s U-turn, he had been tearful on the phone to the Guardian, saying: “I’m not the same person any more. I’m scared. I feel like I’m running out of options.”

The Home Office said it would not comment on an individual case.