The thesis traces the development of the political protest strike as a new tactic within British trade union practice. This tactic evolved in response to government interference in the internal affairs of trade unions. The main thrust of the work concerns the study of the processes of mobilisation and demobilisation within the formal and informal machinery of union decision making and government. The dissertation contains the first attempt to record systematically response rates to these protests nationally and regionally, and over time. A statistical series has been created which has made it possible to test for relationships between political strike action, general industrial militancy and changing levels of unemployment. The thesis can be regarded as a contribution to the literature on trade union government structure and internal politics, and to that on industrial conflict. It reveals the importance of ideological factions which operate within unions, and suggests that conflict between these factions is the most important source of division in the internal politics of trade unionism. It highlights the importance of activists and lines of argumentation in the process of mobilisation/demobilisation. The thesis focused specifically on the AUEW(E) and on the Clydeside and West ~idland regions to allow for comparative study and to test for the regional impact of factional organisation on response rates