Questions about the political influence of organised interests are at the heart of democratic theory and political science. Yet comparatively little is known empirically about the effectiveness of different power resources in policy struggles and how organised interests succeed or fail to employ these resources to achieve desired political outcomes. The main factors behind the empirical neglect of political influence include problems of measurement and a scarcity of relevant data. To address this problem, a newspaper analysis was conducted to compile a data set of 163 policy proposals advanced by UK governments between 2001 and 2007 and to record the reported policy position of organised interests. The data are used to assess frequently voiced expectations in the literature about organised interest politics and political influence in a new light. The results show that support from interest groups is positively related to a proposal becoming policy. The positions of business groups are no better reflected in policy outcomes than those of non-business groups. Donations to political parties are unrelated to the extent to which policy outcomes are in line with a firm's policy positions.