Britain's National Health Service (NHS) is a universal, single-payer health system in which the central state has been instrumental in ensuring equity. This article investigates why from the 1970s a policy to achieve equal access for equal need was implemented. Despite the founding principle that the NHS should “universalize the best,” this was a controversial policy goal, implying substantial redistribution from London and the South and threatening established medical, political, and bureaucratic interests. Our conceptual approach draws on the advocacy coalition framework (ACF), which foregrounds the influence of research and ideas in the policy process. We first outline the spatial inequities that the NHS inherited, the work of the Resource Allocation Working Party (RAWP), and its new redistributive formula. We then introduce the ACF approach, analyzing the RAWP's prehistory and formation in advocacy coalition terms, focusing particularly on the rise of health economics. Our explanation emphasizes the consensual commitment to equity, which relegated conflict to more technical questions of application. The “buy-in” of midlevel bureaucrats was central to the RAWP's successful alignment of equity with allocative efficiency. We contrast this with the failure of advocacy for equity of health outcomes: here consensus over core beliefs and technical solutions proved elusive.