Since 1997, welfare reform has been a defining feature of the UK's Labour government. This article assesses the extent to which the new aspiration to reduce the number of incapacity benefit claimants by one million within 10 years is deliverable. The assessment is based on a model of flows on and off incapacity benefits and their impact on the stock of claimants. In particular, the analysis takes account of the major geographical variations in the distribution of incapacity claimants and the ability of Britain's divergent regional economies to absorb substantial numbers of extra workers. The article concludes that without an accelerated revival in the economies of the North, Scotland and Wales, Labour looks set to fall short of the one million target.