The PSP led the cabinet under Pattom A. Thanu Pillai as chief minister of State of Travancore-Cochin from March 1954 to February 1955. In 1955 a faction led by Ram Manohar Lohia broke from the party, reusing the name "Socialist Party".[5] The PSP again came to power in the new state of Kerala under Pattom A. Thanu Pillai from February 1960 to September 1962. In 1960, Kripalani left the party and in 1964, Asoka Mehta joined Congress after his expulsion from the party.
At the party's first general election in 1957, the PSP won 10.41% of the total votes and 19 seats in the Lok Sabha.[7] However, the party's vote share continued to decline over the next few elections. It won 6.81% of the total votes and 12 seats in the Lok Sabha in 1962,[8] 3.06% of the total votes and 13 seats in the Lok Sabha in 1967[9] and only 1.04% of the total votes and only 2 seats in the Lok Sabha in 1971.[6][10]
^Braunthal, Julius (ed). Yearbook of the International Socialist Labour Movement. Vol. II. London: Lincolns-Prager International Yearbook Pub. Co, 1960. p. 38
^Singh, Mahendra Prasad (1981). Split in a Predominant Party: The Indian National Congress in 1969. Abhinav publications. p. 69. ISBN9788170171409. Retrieved 18 July 2024. The support for the decision was more solid among the left-wing parties; in addition to the Communist Party of India(CPI), Communist Party of India-Marxist(CPI-M), Samyukta Socialist Party(SSP), and Praja Socialist Party(PSP)...
^Lewis P. Fickett Jr. (September 1973). "The Praja Socialist Party of India—1952–1972: A Final Assessment". Asian Survey. 13 (9): 826–832. doi:10.2307/2642762. JSTOR2642762.