Singh was convicted for alleged involvement in four bomb attacks in Punjab province that killed 14 people in 1990.
Lawyer Rana Ilamuddin Ghazi filed the petition on Monday in the Lahore high court in which he contended that Sarbajit was awarded death sentence by the trial court while the high court and the Supreme Court rejected his appeals. Even former Pakistan President Pervez Musharraf dismissed his mercy petition, he said.
Ghazi claimed Dalbir Kaur, the sister of Sarbajit, was currently on a visit to Pakistan and she had appealed to President Asif Ali Zardari to commute her brother's death sentence into life imprisonment and release him from jail. He said the president could not exercise his power under Article 45 of Constitution without the consent of legal heirs of the persons who were killed in the blasts.
Sarabjit's family has denied the charges against him, saying he had crossed the border in an inebriated condition. Sarabjit's execution was indefinitely put off following the intervention of Prime Minister Yousuf Raza Gilani in 2008.
