Commonly, voluntary organisations are formally accountable to their memberships, but the rights of members to influence organisational policies are often minimal. Members may be recruited by organisations to provide funding, legitimacy and voluntary help; members may join in order to obtain material benefits, to express support for organisations’ goals and, in some cases, to influence policy. The disjunction between these two sets of expectations can lead to disputes in large voluntary bodies, especially those whose members hold a wide range of ideological positions. This creates problems for those running the organisations, who both have to account to a variety of other groups and also maintain their public legitimacy. Illustrations of some of these issues are drawn from environmental organisations, particularly the National Trust.