The union was founded in 1887 as the Tea Operatives and General Labourers' Association, to organise opposition to a cut in wages for workers involved in unloading and processing tea at the East and West India Dock Company's Cutler Street warehouse.
From the start, it included other supportive workers, with secretary Ben Tillett working at nearby Monument Quay Warehouse.
By the end of the year, it had 30,932 members, and had been renamed as the "Dock, Wharf, Riverside and General Labourers' Union", reflecting the broader base of its membership.
However, most dock labourers working in the docks on the south bank of the River Thames instead joined a new rival, the South Side Labour Protection League, in protest at the degree of centralisation in the Dockers' Union, and its refusal to allow branch meetings to take place in pubs.
[4] By this time, it had lost most of its members in London, but continued to grow as more workers joined elsewhere in the country.