 In 1980 he was elected to Kerala Legislative Assembly from Piravam Constituency and became Minister for Industries in E. K. Nayanar Ministry.He is the chairman of Joint parliamentary committee to probe the alleged scam in the grant of 2G spectrum and telecom license from 1998 to 2009.He is the Official spokesperson of All India Congress Committee (AICC)

BJP has accused Chacko of altering the JPC report on 2G case and the Congress government steamrolling the report for covering corruption.