At the start of the 1990s trade unions were reeling from a decade of Thatcherism, in which their density amongst employees had been whittled down to 35% by 1990. Several explanations for the decline have vied for attention: the changing composition of industry and of the economy generally, with more part‐time work, fewer large‐scale establishments, the collapse of manufacturing industries and so on; the changing legal environment; the distinctly uncongenial macroeconomic environment, which with lowish inflation and mass unemployment was a discouragement to membership (see for example Disney, 1990; Green, 1991). Such explanations have varying implications for unions' future prospects. For example, if the changed level environment were the key factor, one would predict a further decline of union membership in the 1990s, unless there were a change of government and a wholesale repeal of Thatcherite trade union laws (which is not to be expected). A distinction has been drawn in the literature between the structural factors that determine the social context in which individual employees make their decisions with regard to union membership, and the varying preferences that individuals may have in favour of or against unions. Attempts have been made to show that despite years of attacks from Thatcherism, it is not so much the attitudes and commitment of workers to unions that has changed, as the opportunities that they face. Thus it is said that for many the reason that they left unions is because unions simply were not available at the new workplaces (Gallie, 1989).