The aim of this article is to examine the politics of competition policy in the United Kingdom by taking into account regulatory cooperation at the European Union level. Adopting a multiple streams approach, the article follows a bottom-up approach placing domestic politics at the heart of the puzzle. The analysis leads to four conclusions. First, pace-setters, such as the UK, may not be interested in playing one dimension of the regulatory competition game, that is, trying to influence the development of EU policy. Second, incongruence between domestic and EU regimes does not necessarily produce change at the domestic level. Convergence is not a top-down process. Third, the activating stimulus for change may be external (the EU), but the process is basially of domestic politics. Fourth, to the extent that the removal of political discretion characterizes a more transparent and strictly enforced regime, British competition policy provides empirical support for the hypothesis that the interaction of regulatory competition prior to regulatory cooperation leads to convergence to the top.