Background In dual systems of post-secondary education, a structural separation is maintained between institutions of higher education and those establishments whose main activity is styled further, technical or vocational education. The shift to higher education and, more recently, the drive to near-universal access have called into question this tertiary division of labour. At the same time, a more complex, dynamic and dispersed environment for knowledge production and skills formation has challenged some of the assumptions underpinning dual sector regimes. Under what conditions do dual systems give way to more integrated and unified arrangements? Or why, in other cases, do such systems retain their attraction and significance for national governments?Theory and methodDrawing on theories of differentiation in the study of higher education (Alexander and Colomy, 1990; Huisman, 1995), together with the elite-mass-universal typology originally developed by Trow (1973), the paper compares the different responses to tertiary reform in the four countries of the United Kingdom (England, Scotland, Wales and Northern Ireland). Each country has long operated a dual system but, following a period of mass expansion in higher education and coinciding with administrative and then political devolution, the path taken in Scotland has diverged from that in England. While the Scots have chosen to merge their funding bodies, and Wales and Northern Ireland have sought to align their sector arrangements, the English have reaffirmed their commitment to dual and divided structures.Data on the growth trajectories and patterns of higher and further education over the last twenty years are assembled to permit 'home international' comparisons of the size, shape and scope of their post-secondary systems. Similarities and differences are discussed in relation to the findings of other home country comparisons (Raffe, 2000) as well as relevant domestic and international education policy literatures (Parry and Thompson, 2002; Tapper and Palfreyman, 2005). Results and implicationsThe contrasting policy dispositions of Scotland and England are explained in terms of the different character of their elite-mass transitions, with Wales closer to the English example and Northern Ireland closer to the Scottish model. In England, this transition was accomplished on the basis of recruitment to the first degree in higher education establishments. In Scotland, it was short-cycle higher education in further education colleges that took participation beyond mass levels. Apart from the smaller size and greater intimacy of its post-secondary system, it was sheer scale of higher education in the Scottish further education sector that, it is argued, provided the trigger and main justification for tertiary reform in the post- devolution era. England, on the other hand, sought to reach Scottish participation levels on the basis of 'structured partnerships' between institutions on each side of the dual system. In the English context, where just one in nine higher education students were taught in further education settings compared to one in four Scottish students, dual structures proved no barrier to collaboration between the two sectors. Indeed, there is evidence to suggest that franchise partnerships (where colleges are funded by universities to 'deliver' some of their courses) are well-suited to the kinds of short-cycle, short-order and short-life qualifications that are intended to help close the 'skills gap' and broaden the social base of higher education. Furthermore, a dual system has proved highly functional for both sets of institutions. For universities, franchising enabled them to grow even when capacity constraints had been reached and, conversely, it allowed them to withdraw these numbers when expansion was curtailed. For colleges, such relationships brought additional resources, higher status teaching and more progression opportunities for their own students. In contrast to Scotland, where higher education in further education was owned by the colleges and constituted a discrete (parallel) system, the combination of competition, collaboration and dependence under English conditions was always less likely to loosen the hold of dual arrangements, at least in the short term.