In three experiments, we examined how people negotiate on behalf of a constituency in which opposing factions send different signals. Participants negotiated as sellers on behalf of a group consisting of factions that favored either a cooperative or a competitive negotiation. Experiment 1 (N = 61) showed that representative follow the majority of their constituents, yet competitive (but not cooperative) minorities could challenge the majority's influence. Experiment 2 (N = 132) replicated this finding across different decision rule conditions. Competitive minorities were influential, no matter whether the group would decide unanimously or with majority vote. Experiment 3 (N = 87) showed that competitive members had more influence than cooperative members, even when factions were equally large. We conclude that the influence of a minority faction in intergroup negotiation depends on the specific content of the faction's message, and its strategic implications. We discuss implications for negotiation research and intergroup theories.