The final appeal for Asia Bibi, the Christian mother sentenced to death for blasphemy in Pakistan, has been postponed, Christian Today has been told.

Wilson Chowdhry, of the British Pakistani Christian Association (BPCA), said this morning that the appeal had been adjourned for an indefinite period after the judge refused to hear the case.

Justice Iqbal Hameed ur Rehman said he could not preside over the case, which was due to be heard in Pakistan's Supreme Court today, because he had also tried the murderer of Salman Taseer, the Governor of the Punjab who was assassinated in 2011 after publicly defending Bibi.

"I was a part of the bench that was hearing the case of Salmaan Taseer, and this case is related to that," the judge told the court.

Bibi, real name Aasiya Noreen, is from Ittan Wali, a rural village in the Sheikhupura District of Punjab in eastern Pakistan, about 60 miles west of the capital Lahore.

She was arrested in June 2009 and sentenced to death in November the following year for allegedly blaspheming against the Prophet Muhammad during an argument with fellow farm workers.

She has consistently denied the charges.

Pakistan's repressive blasphemy laws prescribe life imprisonment for the desecration of the Qur'an and the death sentence for "defiling" the Prophet Mohammad, and accusations of incidents have often prompted mob violence. According to the Centre for Research and Security Studies in Pakistan, more than 62 people have been killed in such incidents since 1990. More than 40 people are currently on death row for blasphemy, the majority of whom are members of religious minorities.

Bibi, however, is the first woman to be sentenced to death in Pakistan on blasphemy charges.

Christian Today had previously been told by Christian Solidarity Worldwide's (CSW) South Asia team leader that "if there is any hope of Asia getting justice, it's through the Supreme Court".

The postponement of her appeal will therefore come as a disappointment to campaigners, who have urged Pakistan to release her free of charge.

The CSW source did say on Monday, however, that judges in blasphemy cases are often threatened by Muslim hardliners, which could affect the outcome of her appeal.

"We've seen how politicians who have spoken up have been attacked. Salman Taseer and Shahbaz Bhatti, both killed in 2011, were directly involved in speaking out against the arrest and conviction of Asia Bibi. We have also seen and heard of cases where judges who are presiding over cases involving the blasphemy laws have received threats to their lives and have had to flee the country. So as much as the Pakistani Supreme Court would take a very objective approach, history has taught us that even judges at that level are open to discrimination and threats to their life," he said.