Entered politics through Trade Union activities; became member of Communist Party in 1940.
Imprisoned for five years and six months. Went underground for four and half years - 1946 following the Punnapra Vayalar struggle, 1954,1965 and 1975 while leading various agitations against anti-democratic policies of the then State and Central governmants during Emergency.
Was Secretary, CPI(M) State Committee from 1982 to 1990. Was Convenor, LDF from 1996 to 2000. Leader of Opposition from 1992 to 1996 and 2001 to 2006.
Was chief editor, Deshabhimani.
Now serves as member of CPI(M) State Committee, State Secretariat, Central Committee and Polit Bureau.
Elected to Kerala Legislative Assembly - 1967, 1970, 1991 and 2001.