He served as a Central Committee member of the Revolutionary Socialist Party (RSP) and president of the United Trade Union Congress (UTUC).
[3] He contested the 1960 Kerala Legislative Assembly election, standing as a candidate in the Thrrikkadavur constituency.
[4] In 1965 he contested the Eravipuram assembly seat, finishing in second place with 18,458 votes (35.55%).
[9] Between 25 January and 20 October 1981 he held the post as Minister for Local Administration in the E.K.
[10] He was the opposition candidate for the post as speaker of the Kerala Legislative Assembly in June 1982, but was defeated by 74 against 61 votes.
Unni contested the Quilon Lok Sabha seat in the 1984 Indian general election.
[12] He again contested the Quilon seat in the 1991 Indian general election, finishing in second place with 342,796 votes (46.63%).