Ranasinghe served as the JVP organising secretary from 1983 until his death in 1989. Piyadasa joined the JVP as a GCE Advanced Level student, and became an active member during the 1971 JVP insurrection. He was later arrested in 1971 and transferred to Anuradhapura from the Kelaniya Vidyalankara University Camp and the Ridiyagama Outdoor Camp. Later, a group of JVP activists including Nandana Marasinghe raided the Anuradhapura prison on June 13, 1972 and rescued 32 JVP members including Piyadasa, Heenbanda Wanasinghe and Akuresse Francis. Although Piyadasa was charged with assaulting the Walasmulla police on April 71, he was acquitted and released in 1976.