Former external affairs minister Sushma Swaraj was on Tuesday night admitted to AIIMS and her condition is very critical, hospital sources said.
The sources said she was brought to AIIMS at 10:15pm and was straight away taken to the emergency ward.
A number of senior ministers were rushing to the All India Institute of Medical Sciences.
Swaraj had put out a tweet in the evening congratulating Prime Minister Narendra Modi after the Centre's bold move to revoke special status for Jammu and Kashmir and bifurcate the border state into two Union Territories secured Parliament's approval.
"Thank you Prime Minister. Thank you very much. I was waiting to see this day in my lifetime," she said.
Swaraj had a kidney transplant in 2016.