This thesis deals with the working class of two advanced capitalist countries and focuses upon ideological conflict within working class organizations such as trade unions and political parties., The outcome of such conflicts within working class organizations is considered to be an expression of the state of working class consciousness at a given time. Within this broad context particular attention is paid to the ideology of social democracy which has been dominant in working class organizations in both countries during the modern period albeit to different degrees. The thesis uses a comparative approach and pays considerable attention to the interaction between the working class and its societal environment- the political economies of the two countries, the activities of the capitalist class and the impact of its ideology upon the working class. Using this approach the thesis deals with the emergence of social democracy as the hegemonic working class ideology, its main features particularly as they were developed in the post-war period, the emergence of possible contradictions between social democratic parties and ideology, and their working class supporters, and, utilizing an historical analysis of previous ideological shifts in working class organisations, the possibility of social democracy being superceded in its hegemonic role is considered. In dealing with such matters the issues of nationalization and incomes policies were· judged to be especially salient and are discussed in some detail. In the course of this study theories which posited an end to ideological conflict in the advanced capitalist societies are considered' and rejected. The past, present and future of social democracy, of ideological conflict, and of the working class itself, was found to be considerably more dynamic, complex and open to change than such theories had imagined. / Thesis / Doctor of Philosophy (PhD)