[2] He was a founding member of the United National Party (UNP) entering politics in 1928, two years after he passed out as a proctor.
[2] He then contested and was elected onto the Kalutara Urban Council, a position he retained for thirty years.
[2] In 1952 he contested the second parliamentary elections for the UNP in the Kalutara electorate successfully defeating the sitting member, Cholomondeley Goonewardene, from the Lanka Sama Samaja Party, by 332 votes (a margin of just under 1% of the total vote).
[4] He was also the owner of the Neboda Omnibus Company and the chairman of Free Lanka Finance Ltd.[2] He also, as a board member of Global Films,[6] produced several films including Kalu Diya Dahara, which debuted Ravindra Randeniya, and The God King, which was directed by Lester James Peiris.
[4] Cooray died on 2 June 1998, at the age of 96, the oldest surviving member of the United National Party.