Demonstrations by doctors and staff against healthcare cuts and privatization measures introduced by the Popular Party (PP) have become a regular feature outside the hospital on Thursdays.
But the admission of Cifuentes on Tuesday after being knocked off her scooter led to chants this week of "Let her go private!"
Madrid politician Cifuentes was taken to La Paz with broken ribs and damage to her lung which required an emergency operation to stop the bleeding.
Spanish daily 20 Minutos reported that her condition was said to have improved slightly but that she remains in a stable but serious condition.
She is not believed to have suffered brain or nerve damage in the accident, according to hospital sources.