PPP Punjab president and former federal information minister Qamar Zaman Kaira said India's reaction on Mr Jadhav's death sentence was "natural".
"In fact Nawaz Sharif government has failed to tell the world about the charge sheet on Jadhav. Had India arrested such a Pakistani spy it would have propagated a lot in the world," he said.
Pakistan's former attorney general Anwar Mansoor Khan said Jadhav can file a review appeal before the army chief or the Supreme Court against his sentence.
"In case of rejection of his petition, he may file mercy plea before the President," he said, adding this is a long process and it may take more than two years.
According to ISPR, Jadhav alias Hussein Mubarak Patel was arrested on March 3, 2016 from Mashkel area of Balochistan for his "involvement in espionage and sabotage actives" in Pakistan's restive Balochistan province and Karachi city.
India had acknowledged that Mr Jadhav had served with the navy but denied that he has any connection with the government.