Lanka Sama Samaja Party A process of reunification was initiated between the LSSP and the Bolshevik Samasamaja Party (BSP) in 1950, which was opposed by Gunawardena as a result he left the LSSP and formed a new party, Viplavakari Lanka Sama Samaja Party (VLSSP) in 1951. The VLSSP entered into an electoral alliance with the Communist Party and contested the 1952 general election, in which his wife Kusumasiri Gunawardena was returned to parliament from Avissawella as the only candidate from the VLSSP to be elected. Minister of Agriculture, Food, and Co-operatives He led the Viplavakari Lanka Sama Samaja Party (VLSSP) since 1951 and as a constituent party formed the Mahajana Eksath Peramuna (MEP, Peoples' United Front) in 1956 under the leadership of S.W.R.D. Bandaranaike to form what it call the "first people's government" in 1956 general election. At that election, in 1956, he won the Avissawella seat with a large majority and was appointed as a key member of the Bandaranaike's cabinet as the Minister of Agriculture, Food, and Co-operatives. He is remembered as the architect of the Paddy Lands Act which brought relief to the tenant cultivator and spearheaded the Port and Bus nationalization, introduction of Multipurpose Co-operatives movement and establishing of the Co-operative Bank. At the 1959 May Day rally, Gunawardena claimed that the government was threatened by a conspiracy within and on 18 May 1959, Gunawardena resigned from his ministerial position with other VLSSP members citing differences with right wing factions of the Bandaranaike's cabinet. Bandaranaike was assassinated on 26 September 1959. Mahajana Eksath Peramuna In 1959, he reformed the VLSSP into the Mahajana Eksath Peramuna (MEP) which was a leftist in ideology, but was not Trotskyist. MEP contested the March 1960 general election winning ten parliamentary seats, however this number was reduced to three in the July 1960 general election. Gunawardena retained his seat in parliament on both occasions and later the MEP joined in with the LSSP and the Communist Party to form the United Left Front. Minister of Industries and Fisheries In 1964, the Sri Lanka Freedom Party government of Sirima Bandaranaike lost its majority in parliament after over its move to nationalize Lakehouse Newspapers and the defection of C. P. de Silva. In the election that followed in 1965, only Gunawardena was elected parliament from the MEP and he joined the national government led by Dudley Senanayake and was appointed as the Cabinet