How do lobbyists get their way and what is the consequence for democracy of their strategies? It is frequently asserted that lobbyists appeal to the public interest to strengthen their proposals. This paper empirically corroborates this claim through four case studies cutting across different European cultural clusters and political systems. The paper unpacks how businesses communicatively construct a link between their private interest and the public interest. The findings illustrate the flexibility of the public interest argument and hence also the potential problem. If everything can be made out to be in the public interest, the concept becomes empty and easy to capture for special interests. At the same time, unpacking the communicative construction helps in critically evaluating lobbyists’ claims of working in the public interest.