 In association with the Malabar Socialist Party he organised various anti-war activities during the Second World War.He was elected Vice President of All Travancore Coir Factory Worker's Union and was fined Rs.1000 and imprisoned for two years for allegedly making provocative speeches at Punnapra which resulted in mass rebellion.Disillusioned by the Congress, Thampi joined the Communist Party of India in 1947 just like other prominent leaders like E.M.S.