This article explores the paradox of the two large ‘general’ workers’ unions - the former Transport and General Workers’ Union (TGWU) and the National Union of General and Municipal Workers (NUGMW) - which from their militant origins to within a comparatively few years were seen as undemocratic, moderate in industrial tactics and right-wing in labour politics - ‘pillars of conservatism’. In due time they moved from the fringes to centre stage, acquiring one in four of all trade-unionists, and dominating with their block votes the decisions of the Trades Union Congress and the Labour Party conference. Even more dramatic was the apparent overnight conversion to left-wing views within the TGWU when Frank Cousins became general secretary in 1956. Then under his successor, Jack Jones, responding to the dynamic of shop-floor organization, the TGWU radically changed its ethos and government. The NUGMW, with David Basnett as general secretary from 1973, also moved away from its long-standing positions but its government remained unchanged. But in 1979 the economic and political environments within which the unions were operating completely changed.