Abstract. The evolving methodology of regulation theory is explored, with particular reference to the problematic of uneven development. With a concentration on the subnational scale, the notion of localised modes of regulation is critically examined. With a view to operationalising some of these regulationist concepts, an analysis of the geographical contradictions of Thatcherism is presented. Thatcherism, it is suggested, should be interpreted as a failed or failing regulatory experiment, the contradictions of which are manifest in a variety of ways, including in the geographical sphere-in the collapse of the economy of the South East of England (Thatcherism's 'heartland' region) and in Britain's continuing crisis of uneven development. There is scope, it is argued, further to spatialise regulation theory through methodological refinement, and through analyses of regional restructuring and crisis."When crises endure, orthodoxies fade" (Boyer, 1990, page xxiii).Regulation theory has been enormously influential in recent years, providing as it does a means for interpreting-possibly even responding to-the present global economic malaise. We will argue here that a regulation approach can continue to yield insights into contemporary restructuring processes, but that in order to do so the theory itself needs to be refined. We consider two areas in which some further theoretical development is needed. First, the theory's rather abstract conception of social regulation must be unpacked, and analytical tools developed which are appropriate for concrete research. Second, the theory is articulated primarily at the level of the nation-state and contains no explicit conception of uneven spatial development. This void must be filled if regulation approaches are to be deployed at either the subnational or the supranational scales of analysis. By clarifying some of the more important regulationist concepts and propositions, by providing some pointers for further theoretical development, and by focusing on the question of the social regulation of uneven development at the subnational scale, we hope in this paper to make a constructive contribution to regulationist research. In so doing, we aim also to shed new light on the current debates around flexible accumulation and the politics of post-Fordism, in which the implications of regulationist approaches have sometimes been misread.Popularised in analyses of the breakdown of Fordism and, more controversially, the rise of a potential successor-regime of flexible accumulation, regulation-theoretic approaches have been much used, though perhaps just as often abused. Certainly the terminology of regulation theory has passed easily into mainstream academic discourse. Devices such as regimes of accumulation and modes of social regulation are, however, more than labels. Too often they have been casually applied, robbed of their underlying meaning, and misleadingly divorced from the conceptual architecture of regulation theory, nowhere more so than in premature treatments of