What motivates a political party to develop overseas development volunteering projects for members? How do such activities affect individual volunteers and the party, more broadly? To address these questions, this paper analyses the UK Conservative Party’s international development volunteering projects. Our data comprise 38 interviews with former volunteers and participant observation of one volunteering project in Rwanda in 2017 by one author. This predominantly self-reported data are supplemented with publicly available sources. We draw on employer-supported and state-supported volunteering literature to develop a framework for analysing drivers and effects of party-supported volunteering. We argue that political parties are under-researched sending communities, and that development volunteering constitutes a strategic resource that can be invoked to legitimise engagement with, and authority in, international development as part of the everyday political identity of Party members. As such, how volunteering is used to signal authority in a policy area warrants further research.