Following the death of his father, Rajapaksa left school at age sixteen and returned home together with his brothers, to assist his widowed mother.
Rajapaksa first entered the political arena in 1931, when he supported the Communist Party leader, Dr. S. A. Wickramasinghe, who contested the seat of Morawaka at the first State Council election.
In the State Council he worked as a group, with Dr. S. A. Wickremasinghe, Dr. N. M. Perera, Philip Gunawardena and Leslie Goonewardene in the anti-imperialist and progressive movement.
On 18 May 1945 he died unexpectedly of a heart attack at the age of 48, whilst serving on the State Council.
His position on the Council was filled by his younger brother Don Alvin, who was elected unopposed.