Rapport management is argued to be a critical antecedent of voter support in election campaigns, as it can motivate cooperation. However, little research has been conducted exploring how rapport is managed in such practice. In the present study, the campaign leaflets of four political parties in Sheffield Central constituency for the 2017 UK general election were analysed in relation to rapport-management strategies. Three domains of discourse were identified and classified in terms of one or more of the six principles of persuasion: Reciprocity, Consistency and Commitment, Social Proof, Authority, Liking, and Scarcity. The findings showed that Reciprocity and Liking were the commonly employed principles in the rapport-management strategies. These two principles were established in the leaflets by justifying and explaining credentials. Authority played a major role in influencing the functioning of the other principles in the rapport-management strategies. Specifically, the more authority a party had, the stronger the commitment made to act as rapport-management strategies. In contrast, the less authority a party had, the greater social proof and scarcity were involved in the strategies.