The link between descriptive representation (being member of a disadvantaged social group) and substantive representation (defending the interests of that group) continues to be one of the most hotly disputed issues in social sciences. The political representation of social classes in this perspective has long time been neglected in research, as the main focus has been on women and ethnic minorities. It will be argued in this paper that class is still relevant in contemporary society and that due to the ‘catch-all’ approach of (social-democratic) parties and to the lower levels of recognition of blue-collar workers in the viewpoints of labour parties, the presence in Parliament of individuals of a particular social class (re)gains relevance The effect of these changes on the substantive representation of labour interests will be investigated during three periods in the history of the Belgian House of Representatives: a period when the main aspiration of social-democratic parties was still the defence of labourers’ interests (1950s), a period when the ‘catch all’ process had already widened the scope of these parties but when there were still blue collar MPs present in these parties (1980s) and a period when there were no longer blue collar MPs on the social-democratic benches in Parliament but when they started to appear in extreme right parliamentary parties (end of the 1990s).