Sri Lanka Freedom Party Member of parliament C. P. de Silva was brought into active politics by
Herbert Sri Nissanka, who was the secretary of the
Sri Lanka Freedom Party. He contested in the
general elections in 1952 and was elected to parliament from
Polonnaruwa from the
Sri Lanka Freedom Party defeating the incumbent
P. L. Bauddhasara. He became severely ill at a cabinet meeting on 25 August 1959 after consuming a glass of milk and was flown to the
United Kingdom for medical treatment. During his absence Bandaranaike was assassinated on 26 September 1959 and
Wijeyananda Dahanayake, who was the acting leader of the house was appointed as prime minister by the Governor General. De Silva returned to the island soon after and was appointed as Minister of Agriculture and Lands in the caretaker cabinet. On 12 December the Freedom Party met and elected De Silva as the new president of the party succeeding Bandaranaike. Thereafter the party executive committee authorized him to request the Governor General to remove Dahanayake and replace him with De Silva as the prime minister of the caretaker government. The Governor General acknowledged receipt of the request but did not act on it. Soon after De Silva resigned from his cabinet ministry.
Minister of Power and Irrigation Sri Lanka Freedom Party selected Bandaranaike's widow,
Sirima Bandaranaike as the party leader for the
1960 July general elections. The party won the election and formed a government, with Sirima Bandaranaike becoming the first woman prime minister in the world. C. P. de Silva was appointed the Minister of Power and Irrigation, and leader of the house, once again serving as the senior member of the cabinet until he was surpassed by the Prime Minister's nephew,
Felix Dias Bandaranaike who soon became the prominent figure in the government. C. P. de Silva was soon sidelined by the Bandaranaikes based on caste issues. He briefly served as Minister of Finance in 1962. He established two schools in Minneriya; Central College and the
Polonnaruwa Royal Central College.
Sri Lanka Freedom Socialist Party C. P. de Silva formed the
Sri Lanka Freedom Socialist Party which in coalition with the
United National Party (UNP) contested and won the
general elections in 1965. He was appointed Minister of Lands, Irrigation and Power; and the Leader of the House in the new national government of Prime Minister Senanayake. During his tenure, he established the River Valleys Development Board to develop the
Udawalawe Project and introduced the Mahaweli Development Authority Act in February 1970 initiating the
Mahaweli Development programme. He contested from the
Minneriya district from March 1960, and was re-elected in July 1960 and 1965. He lost his seat in the
1970 general elections to
Ratna Deshapriya Senanayake, having been a member of parliament for 18 years. ==Death==