The WUI was formed in 1924 as a consequence of the clashes between James Larkin and the incumbent leadership of the ITGWU, subsequent to his 1923 release from Sing Sing and return to Ireland in April 1923. Larkin, still officially general secretary of the ITGWU, clashed bitterly with William O'Brien, who had taken leadership of the ITGWU, the Irish Labour Party and the Irish Trades Union Congress.
