[2] However, the prominent Amalgamated Society of Engineers (ASE) refused to join.

[3] The ASE finally joined in 1905 but, failing to persuade the other members to unite with it in a single industrial union, withdrew again in 1914.

[5] In its early years, the Federation focussed on resolving demarcation disputes,[2] but it soon concentrated on making national agreements for the engineering and shipbuilding industries, allowing the largest union in each trade to take the lead in negotiations.

The confederation then represented the vast majority of unionised workers in the relevant industries.

[9] Since the merger of UCATT into Unite the number of member unions has fallen to four.