Doctors said his condition was "critical but stable."
A host of CPI (M) leaders, including party general secretary Prakash Karat and politburo members Sitaram Yechury and Brinda Karat visited the ailing leader at the nursing home.
CPI (M) state leaders held an emergency meeting yesterday to review the situation arising out of Biswas' illness and decided to share the responsibilities, which he was bearing for the forthcoming assembly polls in West Bengal.
More from rediff