This thesis is an investigation of the interface between service volunteers in Australia and New Zealand and ambulance service organisations using a framework that situates them in a changing cultural and structural environment. This topic is particularly important in a political context where volunteers are viewed as a policy solution to a diversity of social ills, and where recent neoliberal policies and managerial cultural shifts have changed the service environment. Specifically this study focuses on how control and agency are evident within volunteer identity work and how this can inform our understanding of the problems experienced in the integration of volunteers into services. Empirical data was gathered in the form of texts that reflected volunteer identity work at the political level (political speeches of key Australian and New Zealand politicians), the ambulance service management level (ambulance documents and interviews with managers) and ambulance service volunteers (interviews with volunteers and secondary data from open-ended survey questions). A critical discourse analysis (Fairclough 1992, 2003) of the data involved firstly generating broad identity themes from the data. Key texts that strongly reflected identity work were then selected for an in-depth textual analysis. This study found four key identities for ambulance volunteers in use within ambulance services: the Moral Volunteer, the Professional Volunteer, the Staff Volunteer, and the Self-interested Volunteer. These identities reflected a diverse range of volunteer and managerial interests. Volunteer interests were shown to include material and emotional concerns, at a personal and collective level. However, ambulance volunteers were found to lack collective agency, which led to inequitable treatment within ambulance services. Ambulance volunteers were generally under-resourced and under-managed, and the effects of this flowed to rural populations which consequently received a lower standard of service. Based on the empirical findings and drawing on governmentality theory (Foucault 1991a) and critical realist theory (Archer 2000; Bhaskar 1975), an explanatory theory of volunteering is constructed. The concepts of identity and agency allow the complexity of the volunteer/service organisation interface in a cultural and iii structural context to be incorporated into empirical studies. Service volunteers are conceptualised as collectives of individuals with diverse interests and local level concerns. Implications for practice include understanding how the volunteer/service interface is likely to experience ongoing difficulties without changes to organisational structures and changes to ‘thinking’ about volunteers.