Thiruvananthapuram | The health condition of former Kerala Chief Minister V S Achuthanandan remains critical, as his blood pressure and kidney function are yet to become normal even several days after getting admitted to a private hospital here, doctors said on Monday.

According to the latest medical bulletin issued by the hospital, the veteran Marxist leader is responding to medication.

However, his blood pressure and kidney function are still not stable, it said.

The 101-year-old leader was admitted to the hospital last week and is being treated in the intensive care unit by a team of specialist doctors.

His various health parameters are being closely monitored, sources added.

Achuthanandan, a towering figure in Kerala politics, has been battling age-related health issues in recent years and has largely withdrawn from public life.

He is the last surviving member of the group that founded the Communist Party of India (Marxist) in 1964, following the vertical split in the undivided Communist Party.

A lifelong campaigner for social justice and workers' rights, Achuthanandan served as Kerala's Chief Minister from 2006 to 2011.