How does a representative's position in the group influence behaviour in intergroup negotiation? Applying insights from the social identity approach (specifically self-categorization theory), the effects of group member prototypicality, accountability and group attractiveness on competitiveness in intergroup bargaining were examined. As representatives of their group, participants engaged in a computer-mediated negotiation with a simulated out-group opponent. In Experiment 1 (N=114), representatives with a peripheral status in the group sent more competitive and fewer cooperative messages to the opponent than did prototypical representatives, but only under accountability. Experiment 2 (N=110) replicated this finding, and showed that, under accountability, peripherals also made higher demands than did prototypicals, but only when group membership was perceived as attractive. Results are discussed in relation to impression management and strategic behaviour.