In the early 1920s, he quit studies to become a Congress khadi (hand spun cloth became a symbol of self-reliance) worker.
According to his own admission in his autobiography ( Kashtokalpito) he was fully converted to the Gandhian mode of struggle by Vijay Modak, a well known philanthropist and Congress organizer of the Hooghly district.
He had to go underground for some time as during this period the British government of India used various acts to justify physical repression or elimination of political activists not necessarily involved in armed movements.
He suffered from mis-advertent administration of drugs while in jail, but reportedly officially forgave the British surgeon in charge when the latter apologized (autobiography - Kashtokalpito).
On his release he was diagnosed with severe malnutrition and was instructed to maintain a minimal body weight by the reputed physician and Congress leader and the second Chief minister of West Bengal of independent India, Dr. Bidhan Chandra Roy (autobiography-Kashtakalpito).
He lent his support for the selection of Lal Bahadur Shastri as prime minister after Nehru’s death and then of Indira Gandhi.