Former Prime Minister Chandrashekhar, who is suffering from cancer, is in a critical state.
The Samajwadi Janata Party leader has been undergoing treatment at the Indraprastha Apollo Hospital for the past three months, hospital sources said, adding, "He is in a critical state."
Prime Minister Manmohan Singh visited the ailing former premier Chandrashekhar on Saturday night.
The 80-year-old Lok Sabha parliamentarian has been suffering from cancer and has been under intensive care for the past one week.
He held the office of prime minister for only seven months. He resigned on March 6, 1991.