[1] In 1877, on completing his apprenticeship, Banner joined the Bookbinders' and Machine Rulers' Consolidated Union, which he represented as a delegate to Edinburgh Trades Council.
He unsuccessfully argued that the council should focus on campaigning for a nine-hour maximum working day, and that it should not endorse Liberal Party candidates.
[1] In 1881, Banner called a conference of social democrats in Hamilton, trying to use his connections with Keir Hardie in a failed attempt to found a Scottish Labour Party.
In 1888, they began forming the Labour Union, and Banner took an active role until late 1889, when he became convinced that the group would not prove a success.
[1] Banner continued speaking in support of socialism, calling for an eight-hour working day and the formation of the Woolwich Labour Party.
That year, he also won election to the Fabian Society's executive, but resigned soon after as his working hours meant he was unable to attend its meetings.