Human rights and faith groups are urgently calling for more action on behalf of Pastor Yousef Nadarkhani, who faces execution in Iran.
The Christian minister was on trial in Rasht last week, and refused to deny his faith during the court hearing.
He has now re-appeared in court three times, and each time has refused to renounce Christianity when asked to do so by the court. If he continues to refuse, he faces execution.
Pastor Nadarkhani was arrested in October 2009 while attempting to register his church. He was tried and found guilty of apostasy (abandoning Islam) in September 2010. He has been sentenced to death.
The Supreme Court recently asked for a re-examination of his case to establish whether or not he had been a practising Muslim adult before he converted to Christianity.
The court ruled that he was not a practising Muslim, but is still guilty of apostasy because he has Muslim ancestry.
The death sentence is not specifically prescribed for apostasy under Iranian law. The Rasht court has used a loophole in the constitution and based their verdict on fatwas (religious rulings) by the “father” of Iran’s revolution in 1979, currently Iran’s most influential religious leader.
An Iranian official told pro-regime media outlet Press TV that Nadarkhani is guilty of security charges, being a Zionist and running a brothel, rather than of apostasy.
Groups ranging from Amnesty International to Christian Solidarity Worldwide have taken up the case, and say that Iran's latest claims are unfounded.
"It is shocking that the Iranian authorities would even consider killing a man simply for exercising his right to choose a religion other than Islam," said Hassiba Hadj Sahraoui, Amnesty International’s Deputy Director for the Middle East and North Africa.
Nadarkhani's lawyer submitted three edicts from senior clerics in his client's defence. Two seen by by Amnesty cast doubt on even the religious validity of the idea that someone could be executed for wanting to change his or her faith.
"Yousef Nadarkhani is being held solely on the basis of his religious beliefs. He is a prisoner of conscience and must be released immediately and unconditionally," said Hassiba Hadj Sahraoui.
Nadarkhani, born to Muslim parents in the northern Iranian town of Rasht, was arrested on 13 October 2009.
He turned to Christianity at the age of 19, becoming a member of the Only Jesus Church, before being ordained as a pastor in Rasht. He says he was never a practising Muslim.
His arrest may have been linked to the fact that he protested against his child being given mandatory lessons on Islam in school.
Naderkhani refused to recant his beliefs during his four-day trial this week, reportedly telling the judge: "I am resolute in my faith and Christianity and have no wish to recant."