 He became a leading figure in the party, but was expelled in 1907 for arguing that the SLP should not favour the Industrial Workers of the World.He was able to rejoin the following year, convincing the majority of the party to form the Advocates of Industrial Unionism.Generally continuing to work in the metal trades, Bell briefly joined the Singer Company to organise for the Industrial Workers of Great Britain, but was sacked following the failure of a strike in 1911.