This article proposes a framework for exploring how politicians use moral arguments to win support for their policies. It proceeds from the premise that the formulation of such arguments is mediated by three factors that constitute a general context of justification—‘ideology’, ‘argumentation’ and ‘hegemonic competition’. For analytical purposes, the framework reconstructs the process of justification as one in which argumentative strategies are selected, modified and utilised in the light of these factors. The framework is applied to New Labour's case for the New Deals and Flexible New Deal. The analysis reveals that these initiatives and the moral arguments used to promote them are broadly consistent with New Labour's ideology; the arguments are appropriate to the policies; and that New Labour succeeded in setting the agenda on welfare reform.