“…By seeking to undermine the legitimacy of those involved (Beresford & Campbell, 1994), controlling the course of meetings (Williams, 2004), or selectively implementing the suggestions of publicparticipation processes (Milewa, Valentine & Calnan, 1999), professionals and managers are seen to retain control over decision-making processes, or manipulate public participation to ensure that it advances their own interests (Harrison & Mort, 1998;Milewa et al, 1999;Tritter, Barley, Daykin, Evans, McNeill, Rimmer et al, 2003). In order to further their own influence, involved members of the public too are forced to defend their own legitimacy, and so are drawn into a complex discursive game with staff, as each group seeks to assert or undermine the legitimacy of participants (Contandriopoulos, 2004). This paper seeks to further understanding of this process by drawing on a qualitative study of a particular example of public participation-service-user involvement in cancer-genetics services-and the way in which the bounds of legitimacy of this process are contested by those involved.…”