The government was planning to decontrol the mines and railways in 1921. The coal industry was making heavy losses and owners argued that wage cuts were needed. On 31 March 1921, the day of transfer, the miners were locked out. Their leaders appealed to railwaymen and transport workers for a sympathy strike but on Black Friday, 15 April 1921, they refused. This resulted in the end of the unions' 'Triple Alliance'.
As membership diminished, unions experienced a period of consolidation. An important centralising development took place when the General Council of the Trades Union Congress (TUC) was formed in 1921, promoting cooperation between unions. Individual unions retained a large degree of autonomy.
In January 1924, Ramsay MacDonald formed a Labour government with Liberal support. Despite Labour's links with the unions, within a few days there was an extensive dockworkers strike, followed by a tram workers strike. A settlement was worked out, but not before the government had considered invoking the Emergency Powers Act.