Аннотация:Friends of the Earth's (FoE) 'Big Ask' campaign played a critical role establishing the path-breaking UK Climate Change Act (CCA) 2008. FoE exploited the window of opportunity that opened in climate politics during 2006, first to win cross-party support for the Bill and then to strengthen its content. It then rolled-out the 'The Big Ask' across Europe, helped by an innovative collaborative seminar programme with the Foreign and Commonwealth Office. The Multiple Streams Framework is used to identify FoE as an effective policy entrepreneur shaping the agenda-setting process. This contributes to the policy entrepreneurship literature where there are relatively few examples of effective collective entrepreneurship by environmental non-governmental organizations and makes an original empirical contribution through a detailed analytical narrative about a remarkably successful environmental non-governmental organization campaign. Qualitative methodology is employed, drawing on public and private documentary sources and interviews with key campaigners, politicians and officials involved in climate policymaking.