Concerned at Sarabjit Singh's deteriorating condition, India asked Pakistan to send him to a third country for "proper treatment" and said "every endeavour" should be made to save his life.
"We believe that every endeavour should be made to save his life," said a statement issued here by the external affairs ministry.
Sarabjit's wife Sukhpreet Kaur said she wants her husband back.
"My husband is still alive. Please save him. I appeal with folded hands. Manmohan Singh and Sonia Gandhi are sleeping on his plight," she said.
"We met him (Sarabjit) five times. He did not realise that his family was with him. Please bring him back. We have no trust on (Pakistani) doctors," an emotionally charged Swapandeep said.
The family had gone to Pakistan Sunday to meet Sarabjit, who has been admitted to Lahore's Jinnah Hospital after being brutally assaulted by fellow prisoners last week in the city's Kot Lakhpat jail. They were given a 15-day emergency visa to visit Pakistan.
However, the family returned after only three days to take up the case with the Indian government.
Sarabjit, 49, had suffered critical head injuries in the unprovoked and sudden assault by four to five prisoners April 26. He has been on ventilator life support since.
He has been on death row in Pakistan since 1990 after being convicted by Pakistani courts for bomb blasts in Lahore and Multan, which left 14 people dead.
