Born in Stoke Newington, Cant joined the Young Socialist League at the age of fifteen, and immediately became involved with the successful campaign against wage reductions at the Thames Iron Works.
He was part of the majority opposing British involvement in World War I, and wrote extensively in the party newspaper, The Call.
He was then appointed as the BSP's Scottish organiser, and in this role took part in the discussions which formed the Communist Party of Great Britain (CPGB).
On release, he relocated to South Wales, where he spoke in support of miners during their lock-out, then moved to the Soviet Union, working for the International Class War Prisoners Aid Movement and the Comintern.
[1] From the early 1930s, Cant was the CPGB organiser in Nottingham, where he attempted to build support among miners, and was also active in the local co-operative movement.