India's Supreme Court on Monday stayed the death sentence handed down to the lone surviving gunman from the 2008 Mumbai attacks, pending an appeal hearing. "This (appeal) case has to be heard on top priority," Supreme Court judge Aftab Alam told the court. "It is the demand of the judicial system that we have to hear this appeal." Pakistani national Mohammed Ajmal Amir Kasab, one of 10 Islamist gunmen who laid siege to Mumbai for nearly three days killing 166 people, was convicted in May 2010.