The working class is classically defined as that class which must sell its labour-power in order to survive. This was essentially what Karl Marx meant by the proletariat. However, this is hardly a satisfactory definition for late 20th-century developed societies. If there is a working class distinct from the rest of society, then there must be distinctive features to its work and market situations, and indeed there are.
First, in terms of market situation, the working class is defined by the fact that it sells its labour-power in discrete amounts of time (paid by the hour) or output piecework) in return for a wage. In the case of work situation, the working class comprises those who are in an entirely subordinate role, such that this is a key feature of their labour contract. Hence the working class basically consists of those who work in manual or blue-collar occupations. However, none of this should be taken to mean that there is one amorphous working class, since there are a number of ways in which the class is divided into distinct groups. One of these is in terms of skill. There is an upper working class or aristocracy of labour which consists of skilled workers—occupations such as fitters, electricians, and the like—where incumbents have been apprenticed or learned a trade. These constitute about one-third of the working class. The remainder are in so-called semi-skilled or unskilled occupations. A second division is that between those working in primary rather than secondary labour-markets. Some members of the working class have better paid and more secure jobs (in the primary labour-market) than have others. Most skilled workers belong to this primary labour-market. Many female and ethnic-minority workers are found in the lower-paid, more insecure secondary labour-market, lacking standard labour contracts, pension and illness entitlements, paid vacations, and so forth. It is among this group that both unemployment and under-employment (where people find that they have periods of employment and unemployment interspersed on a frequent and irregular basis) are most frequently found. The other notable feature of the working class in developed capitalist societies is that it is shrinking, largely due to a combination of technological change (notably automation), and the decline of the primary and manufacturing sectors. Only about one-third of the economically active would be working class by the definition given here.
The fullest development of the working class in Britain was in the period from the 1890s to the 1950s, when these economic divisions matched and were associated with a complex of cultural and political institutions and practices that gave the working class a cohesive identity and social consciousness organized around so-called ‘traditional’ working-class communities. These institutions included the Cooperative store, the Labour Party, trades unions, and the working men's club, together with solidaristic orientations to industrial and political action, including solid Labour voting (see Michael Savage and Andrew Miles, The Remaking of the British Working Class, 1994). Since the 1950s, these cultural and political aspects of working-class experience have weakened and those who share a working-class market and work situation exhibit a variety of subjective orientations and social identities. Nevertheless, Gordon Marshall et al.'s Social Class in Modern Britain (1984) reported that 49 per cent of respondents mentioned being a manual or unskilled worker as the chief characteristic of the working class, and 16 per cent defined the class as those with low incomes. By the time of the empirical work summarized in Michael Savage, Class Analysis and Social Transformation (2000), a more diverse range of identifications and aspirational life-styles were apparent. Some argue that this points to the ‘death’ of the working class, yet it remains the case that sharp economic contours persist. See also proletariat; middle class; upper class.