Banker and his friend Indulal Yagnik had established Young India and Navjivan publications respectively. They had handed over these publications to Mahatma Gandhi when he entered public life in India. He was one of the early associates of Gandhi. On 10 March 1922, Gandhi and Banker, as publisher and editor of Gandhi's newspaper Young India, were accused of treason and arrested.
Banker had played a major role in Gandhi's activities in Ahmedabad. He participated in the textile mill workers’ strike in Ahmedabad, the 1918 Kheda Satyagraha and the protests against the Rowlatt Act. He was the secretary of the Bharatiya Charkha Sangh which promoted khadi and Charkha.
- Kothari, Urvish (2 October 2018). "How an engineer and 2 high-flyers became Gandhi's men". The Print.
- Mulk Raj Anand; National Council of Educational Research and Training (India) (1987). The Historic trial of Mahatma Gandhi. National Council of Educational Research and Training. p. 24.
- "TRIAL OF MAHATMA GANDHI - 1922". Bombay High Court.