Here are 10 developments in this story
In its latest appeal issued on Monday evening, the government of India said, "it is clear that his condition remains critical...In view of the recent tragic events and present circumstances, we once again appeal to the Government of Pakistan to take a sympathetic and humanitarian view of this case, and release Sarabjit Singh." (Read full text of the appeal)
The government has also urged Pakistan to allow Mr Singh to be moved to India. "We would like to consider the option of transferring Shri Sarabjit Singh to India so that he can benefit from the best medical treatment available here," the statement said.
New Delhi has demanded that the murderous attack on Sarabjit Singh be investigated and that those responsible be identified and punished. It has told Islamabad that Pakistan must ensure the safety of all Indian prisoners in their custody.
Pakistan has so far not indicated any willingness to shift Sarabjit out of Lahore's Jinnah hospital, where he is on ventilator support. The hospital is being treated like a sub-jail.
Earlier today, India denied reports by local Pakistan TV channel that a team of four doctors had advised against moving Mr Singh "outside Pakistan for treatment."
Mr Singh has been comatose since Friday evening when six prisoners hit him on the head with bricks and sharp metal pieces from a tin. The Indian High Commission in Islamabad said today that there was "no change for the better" in Sarabjit's condition.
His family - his wife, sister and two daughters - have been in Lahore since yesterday after Pakistan granted them emergency visas. His sister, Dalbir Kaur, said, "I request my Indian government to please, without further delay, take Sarabjit away from here. And take him where he can be treated well."
Indian diplomats in Pakistan have been given permission to visit Mr Singh in hospital twice a week, Pakistan's Foreign Ministry said today.
His lawyer, Owais Sheikh, has claimed that Mr Singh had received threats following February's execution of Afzal Guru, a Kashmiri convicted for his part in the deadly attack on the Indian Parliament in 2001.
Sarabjit was convicted for a string of bomb attacks in the Punjab province in Pakistan which killed 14 people in 1990. He has been on death row since 1991. His mercy petitions have been rejected by courts and former president Pervez Musharraf. His family says he is a victim of mistaken identity and had inadvertently strayed across the border.
"This Belongs To You": Harshit Rana Celebrates India ODI Call-Up With His Father AIFF Has A Shortlist Of 20 Candidates For India Men's Football Team Head Coach's Job Last Few Weeks Have Been Nothing Short Of A Dream: Suryakumar Yadav Bangladesh Imposes Curfew, Deploys Military As 105 Die In Protests "Jindal Group Executive Showed Porn, Groped Me On Flight": Woman To NDTV Over 300 Indian Students Return Home As 105 Bangladeshis Killed In Protests Joe Biden Is The Best Person To Take On Trump, Says His Campaign Wife Among Two Jailed For Life For Man's Murder In Gurugram: Cops 1,100 Flights Cancelled In US As Microsoft Outage Disrupts Operations Track Latest News Live on NDTV.com and get news updates from India and around the world.