Over the past fifteen years, an interconnected set of regulatory reforms, known as Better Regulation, has been adopted across Europe, marking a significant shift in the way that European Union policies are developed. There has been little exploration of the origins of these reforms, which include mandatory ex ante impact assessment. Drawing on documentary and interview data, this article discusses how and why large corporations, notably British American Tobacco (BAT), worked to influence and promote these reforms. Our analysis highlights (1) how policy entrepreneurs with sufficient resources (such as large corporations) can shape the membership and direction of advocacy coalitions; (2) the extent to which "think tanks" may be prepared to lobby on behalf of commercial clients; and (3) why regulated industries (including tobacco) may favor the use of "evidence tools," such as impact assessments, in policy making. We argue that a key aspect of BAT's ability to shape regulatory reform involved the deliberate construction of a vaguely defined idea that could be strategically adapted to appeal to diverse constituencies. We discuss the theoretical implications of this finding for the Advocacy Coalition Framework, as well as the practical implications of the findings for efforts to promote transparency and public health in the European Union.