From 1893, Larkin developed an interest in socialism and became a member of the Independent Labour Party. In 1905, he was one of the few foremen to take part in a strike on the Liverpool docks. He was elected to the strike committee, and although he lost his foreman's job as a result, his performance so impressed the National Union of Dock Labourers (NUDL) that he was appointed a temporary organiser. He later gained a permanent position with the union, which, in 1906, sent him to Scotland, where he successfully organised workers in Preston and Glasgow. Larkin campaigned against Chinese immigration, presenting it as a threat that would undercut workers, leading processions in 1906 in Liverpool with fifty dockers dressed as 'Chinamen', wearing faux-'pigtails' and wearing a powder to provide a 'yellow countenance'.