EU steel policy offers a particularly good example of how policy ideas can be transposed from the national to the supranational level via advocacy coalitions and policy entrepreneurs. The Treaty of Paris, which founded the European Coal and Steel Community in 1951, gave steel a firm institutional base, and made it a 'special case' within the European Community. Although the Treaty was a hybrid in which liberal principles rested somewhat uneasily against the potential powers given to the High Authority, in the 1970s and early 1980s the Commission adopted a highly interventionist policy in response to the deep crisis in European steel. Consequently, it might have been expected that rival free market ideas would encounter great difficulty in altering the dominant policy frame, but in the late 1980s and 1990s these have successfully infiltrated the steel sector. This article describes and analyses this process, particularly with regard to the effects of the ideological push given to free markets by the Thatcher government in Britain in the 1980s, and a change in the French industrial culture which played an important part in shifting the balance of power in European steel policy.