Legal group Christian Concern has claimed the Home Office has anti-Christian bias after a Christian convert's asylum application has been rejected.
Reza Karkah, a 38-year-old who lives in Bradford, said he believes he would be executed because of his Christian faith if he were deported to Iran.
Christian Concern claims the Home Office doesn't believe a Christian convert would face any risk of persecution by Iranian officials, showing "the need for expertise on the Christian faith to be introduced to the Immigration and Borders department in the government office".
In a tribunal judgment on Mr Karkah's case by the Home Office in 2018, it was judged that if he was deported it would not "expose him to a real act of persecution".
"Mr Karkah's treatment as an asylum-seeking Christian is in stark contrast to how the Home Office processes applications from members of Islamist groups," Christian Concern said in a statement.
"Home Office guidance on assessing asylum claims from members of Egypt's Muslim Brotherhood, for example, implies that senior members of the group should be presumed to be at risk of persecution by the state and therefore granted asylum
unless there is clear evidence that they are personally involved in violence."
According to the Open Doors World Watch List, Iran ranks number nine out 50 of countries most hostile to Christians. The charity said Christianity is seen as a Western influence and a threat and much of the persecution of Christians comes from the Iranian government.
Mr Karkah, who grew up a nominal Muslim, fled Iran for the UK in 2003. After his initial bid for asylum was rejected in 2004, Mr Karkah became a homeless drug addict and a petty criminal.
He met his now-wife on the streets. In 2015 they both became Christians.
After being baptised, Mr Karkah ended his drug habit and has stayed out of the criminal justice system for five years.
Christian Concern said he is active in his local church and helps with outreach to Iranian Muslims and translates church services from English to Farsi.
In November 2016, Mr Karkah made a second application for asylum, but the judge ruled that he lied about being a Christian.
Christian Concern said the assessment was based on a 150-question test, where Mr Karkah answered a number of questions correctly, but failed to identify who betrayed Jesus and the denomination of his independent evangelical church. He also
failed to answer a question on his favourite Bible passage because he misinterpreted the word "passage".
The official decided that his deportation and separation from his wife, who's a British national, and child would be distressing but would "not be unduly harsh".
The Home Office suggested that once Mr Karkah was deported to Iran, he could meet up with his wife and child halfway in a country such as Turkey.
He said he is uncertain about the future despite the renewed application for asylum.
"I feel weighed down and that my life is on hold," he said.
"Knowing that I could be snatched off the street makes me nervous about leaving the house.
"We pray each time we go out that Jesus will have mercy on us. I now have a new life and a new hope. To think that this could be taken from me in a moment is horrible."
Andrea Williams, chief executive of the Christian Legal Centre, said the Home Office needs to be more educated about Christianity.
"At stake here is not just the life of Reza, but also his equally brave yet vulnerable wife, and their beautiful daughter," she said.
"We see in this case, and many others, that the Home Office has not properly understood the nature of Christian faith or the scale of the challenges faced by Christians in Iran.
"We call on the Home Office to grant Reza asylum and for the government to address the ignorance of Christianity demonstrated in its asylum assessments and procedures".
A Home Office spokesperson told Premier: “Individuals are only returned to their country of origin when the Home Office and, in some cases, courts if applicable, deem it is safe to do so.”
Each immigration case is assessed on its individual merits, taking into account the length of time a person has lived in the UK as well as the strength of their social, cultural and family ties to the UK.