Habibollah Latifi's family say he is not member of separatist group but is being punished for his political activism

A 29-year-old Iranian student activist is facing execution tomorrow unless an international campaign launched by human rights groups can persuade authorities to quash his conviction.

Habibollah Latifi, a politically active student of civil engineering at Azad University, in the south-western province of Ilam , is scheduled to be executed in Sanandaj prison tomorrow, following what his lawyer has described as an unfair trial.

His family is pleading with the international community to urge Iran to stop his execution.

"We do not have any other hope than reaching out to the international community," Latifi's sister Elahe told the Guardian. "Please help my innocent brother not to be executed while people of the world are celebrating Christmas."

Latifi, a member of the Kurd minority in Iran, was arrested on 23 October 2007 in Sanandaj, the capital of Kurdistan province, and was taken to prison where he has been kept for the past three years and two months.

Iran says he was a member of Kurdish Independent Life party (PJAK), an armed opposition group and has convicted him of Muharebeh (enmity against God) but his family denies his connection with PJAK and claims the charges were fabricated .

"This is nonsense, they're just angry with his political activities as a student and have charged him with the false claim that he was a member of PJAK, that's absolutely a lie, it's just an excuse for them to execute him," his sister said.

According to Amnesty International, his trial was held behind closed doors and his lawyer was not allowed to be present to defend him. His death sentence was upheld by the appeal court in Sanandaj on 18 February 2009.

Human rights advocate Peter Tatchell, who has campaigned in defence of Iran's ethnic minorities, said: "Iran has a long history of persecuting its Kurdish ethnic minority population, including framing peaceful, lawful Kurdish rights activists on false charges.

He added: "Habibollah Latifi was sentenced to death after an unfair trial in a closed court, where he had no legal representation – clearly in violation of articles 10 and 11 of the Universal Declaration of Human Rights.

"The Iranian authorities should, at the very least, revoke the execution order and schedule a new trial where Latifi can have legal representation, call witnesses and submit forensic evidence in his defence."

Amnesty's Middle East and north Africa director, Malcolm Smart, said: "We are urgently appealing to the Iranian authorities to show clemency, halt the imminent execution of Habibollah Latifi, and commute his death sentence. "

He added: "It is clear that Habibollah Latifi did not receive a fair trial by international standards, which makes the news of his impending execution all the more abhorrent."