On November 1, 1924 to support Vaikom Satyagraha, Savarna procession was set out from Vaikom to Trivandrum under the leadership of Mannathu Padmanabhan.
In 1947 he became a member of the Indian National Congress.
In 1949 Padmanabhan became a member of the Travancore Legislative Assembly.
He was honoured with the title Bharata Kesariby by the President of India.
Sardar K M Panicker called him ‘Madan Mohan Malavya of Kerala’.