This thesis uses the concept of 'emotional ambivalence', understood as a dynamic emotional response to change that unfolds over time, to explore the complex emotions experienced by employees and managers under New Public Management (NPM). The qualitative empirical study is based on two in-depth case studies of English housing associations. Thirty-five semi-structured interviews were conducted across hierarchical levels and organisational documents and research fieldnotes were analysed using thematic and narrative methods. The analysis demonstrates that NPM involves a cultural change from a traditional public sector to a more 'business-like' organisational culture. This thesis critiques dualistic representations of emotion, as either positive or negative, and the use of 'mixed emotion' to explore the complex emotions experienced by organisational members during change. It argues that the emotions experienced by organisational members during NPM-related change are inherently ambivalent. Emotional ambivalence arises from multiple sources and has contradictory emotional elements. A key conclusion of this study is that engaging with organisational members who experience ambivalent emotions in response to change offers an important resource which can be utilised by change managers.