Traditionally, CPA scholarship has either assumed away policy intermediaries completely, or depicted them as corporate mouthpieces. Meanwhile, research on policy intermediaries has portrayed actors such as think tanks, PR firms and lobbying firms as far more active and self-interested. Our study investigates this puzzle by attending to the question: ‘Whose political agenda is expressed by intermediaries during their lobbying on behalf of corporate clients?’ By importing insights from studies of policy intermediaries, and approaching the world of lobbying qualitatively – delving deep into the ‘how’ and ‘why’ of corporate lobbying using ethnographic field data and interviews with corporate lobbyists – we provide a different, more fine-grained picture of the lobbyist–client relationship, in which policy intermediaries shape, adapt and even invent their clients’ agendas. Our study contributes CPA scholarship by (1) providing an analytical distinction between the political agendas of corporate clients and those of their lobbyists, (2) bringing further detail and modification to Barley’s theory of an institutional field of political influence and (3) identifying agency problems between client and lobbyist as a novel explanation for why the financial profitability of CPA investment has been difficult to verify. Moreover, the study brings further sophistication to a burgeoning literature on policy intermediaries by suggesting that lobbyists’ own professional characteristics – such as length of political experience and strength of political convictions – influence how independently of their clients they dare to act.