Born Don Philip Rupasinghe Gunawardena on 11 January 1901 in the rural village of Boralugoda in the Avissawella in the Hevagam Korale.

His father was Don Jakolis Rupasinghe Gunawardena, known as Boralugoda Ralahamy was a local landowner who served as the village headman (Ralahamy) and Vidane Arachchi until he was imprisoned and sentenced to death under martial law during the 1915 Sinhalese-Muslim riots, sentence was later reprieved by the Governor following a petition by his wife.

He was the third child of a family of three boys and seven girls, which included Robert Gunawardena and Caroline Anthonypillai who became leftist politicians.

Having passed his London matriculation, he entered the University College, Colombo to study economics and soon joined the Ceylon National Congress, but was drawn towards the activities of the Young Lanka League.

Instead at the age of 21, he traveled to the United States where he studied economics at the University of Illinois, there he was radicalized and got caught up in the declining labor movement during the Great Depression.

[5][6] In 1929 he went to London, where he participated in mass agitations and anti-colonial movements, excelling as a brilliant orator, trade unionist, and political columnist.

Jawaharlal Nehru and Krishna Menon of India, Jomo Kenyatta of Kenya, Tan Malaka of Indonesia, and Seewoosagur Ramgoolam of Mauritius were some of his contemporary colleagues who later played prominent roles in their respective countries.

In 1936 he was elected to the State Council of Ceylon from his home town of Avissawella, defeating F. A. Obeysekera where he continued his struggle for the betterment of workers and peasants.

Philip Gunawardena was arrested and imprisoned due to his open opposition to the British war effort on the Governor's orders.

However, he soon lost his seat when he was convicted by the district court and sentenced to three months rigorous imprisonment for leading employees of the South Western Transport Company owned by Sir Cyril de Zoysa in a general strike in 1947.

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.

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.

[23] 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.

[25] His seat was contested by his son Dinesh Gunawardena in the 1977 general election and lost to M. D. Premaratne from the United National Party.

[7] His grandson Yadamini Gunawardena was appointed to parliament from the national list of the Sri Lanka People's Freedom Alliance.