He was born with a Silver spoon in his mouth. He was deeply imbued with patriotic fervor from his school days. He left college education half way in response to the call of Mahatma Gandhi and played a pivotal role in the freedom movement. He accompanied the entourage of Mahatma Gandhi during his visit to Orissa in the year 1921. He joined the Indian National Congress and organized Satyagraha in Balasore district. He founded the popular Oriya daily Prajatanta under the ageis of Prajatantra Prachar Samiti.

He joined the Salt Satyagraha (Labana Satyagraha) movement of Mahatma Gandhi and was arrested. He was elected as the President of State Congress Committee in 1937-38. Subash Chandra Bose nominated him as the member of National Congress Working Committee in 1939. He was imprisoned in Ahamad Nagar Jail along with other national leaders. He was released in 1945. Then, he took over the reign of administration as Chief Minister in 1946 and continued till 1950. He joined the central cabinet as cabinet minister and became the secretary general of Central Congress Parliamentary Party from 1952 to 1954. Later, he became the Governor of Maharastra State 1955-56. He became the Chief Minister of Orissa from 1956 to 1960 and a member of Orissa Legislative Assembly. He protested against the emergency in 1976 and was imprisoned. Dr. Mahatab was a great littérateur, writer, historian and statesman of repute. He initiated a system of honoring distinguished writers in a special literary function annually held on Visubha Sankranti Day. He was conferred a Doctorate from Andhra University. He helped the integration of Indian States.