Pakistan’s Supreme Court delayed an appeal into a notorious blasphemy case against a Christian mother on death row on Thursday after one of the judges stepped down, with thousands of security forces deployed following threats from Muslim clerics. Police and troops had been stationed across Islamabad as the court readied to hear a final appeal in the case of Asia Bibi, who has been on death row since 2010. Observers had warned of “tremendous” repercussions in the case. But one of the three-judge bench, Justice Iqbal Hameed ur Rehman, told the court he had to recuse himself, claiming a conflict of interest. “I was a part of the bench that was hearing the case of Salmaan Taseer, and this case is related to that,” he told the court, which was overflowing with journalists, lawyers, activists and clerics. Taseer, a liberal provincial governor, was gunned down in Islamabad in 2011 after speaking out for Bibi. His assassin, Mumtaz Qadri, was hanged earlier in 2016 in a step liberals hailed as progressive, but which brought hardliners into the streets calling for Bibi’s death. Rehman was chief justice on the Islamabad High Court which heard Qadri’s appeal in 2011, according to local media. Observers have called the case a battle for Pakistan’s soul as the state walks a line between upholding human rights and appeasing hardliners. Clerics at the influential Red Mosque in Islamabad warned they would launch a nationwide protest if Bibi is released. “Anyone who defends or protects a blasphemer of the Prophet will themselves be considered guilty of blasphemy,” spokesman Hafiz Ihtesham Ahmed said. He warned against foreign diplomats lobbying for Bibi’s release, saying in a statement that clerics would mobilise the public if she was freed and “everyone will become Qadri”. “All the foreign powers should keep in mind that we won’t let them succeed in their nefarious designs,” Ahmed said at the court on Thursday. Police said up to 3,000 security forces had been sent out across the capital. Bibi’s lawyer Saif-ul-Mulook called the Red Mosque threat “big”. “I hope the government takes it very seriously and takes care of our security,” he told media outside the court on Thursday. Blasphemy is a hugely sensitive issue in Pakistan. Anyone even accused of insulting Islam risks a violent and bloody death at the hands of vigilantes. Rights groups complain the controversial legislation is often abused to carry out personal vendettas, mainly against minority Christians. Bibi was convicted and sentenced to hang in 2010 after an argument with a Muslim woman over a bowl of water. Her supporters maintain her innocence and insist it was a personal dispute, and the Vatican has called for her release. But successive appeals have been rejected, and if the Supreme Court bench eventually upholds Bibi’s conviction her only recourse will be a direct appeal to the president for clemency. If that fails, she could become the first person in Pakistan to be executed for blasphemy.