In the wake of the Non-cooperation movement, Anantahari left his studies and became a whole-time Congress worker, spinning Charkha, weaving and selling khaddar, and agitating for the boycott of foreign goods. After that Mitra, met with nationalist revolutionary poet Bijaylal Chattopadhyay and came to Krishnanagar, Nadia where he met with leaders of the Indian National Congress.[1] In 1924, Mitra actively took part in revolutionary freedom struggle and left for Daksineswar. Police raided his residence at Daksineswar on 10 November 1925 and arrested Mitra along with other activists. He was sent to prison in 1926 for his connection with the Daksineswar Conspiracy Case.[3][4]