Political parties are fragmented entities with complex internal collective dynamics. At times, parties struggle to retain the support of long-term loyal voters and are affected by internal differences around salient policy issues. The present paper strives to investigate intra-party policy-setting by focusing on the case of a three party political system, where an internally divided political party has an ideal policy point at the centre of the one-issue policy space and competes electorally against two opposing parties with ideal points on both sides of the centre. The resulting model assumes transitive policy preferences and sequential interaction for actors, excludes voter abstention and disallows factional breakaway. The analysis of the
model’s equilibriums reveals the mechanism that governs intra-party factional bargaining and voting behaviour in a three-party case. Specifically, it emphasises the fine balance between policy incentives and imperfect information on electoral outcomes that shapes the strategic interaction between factions as well as the voters’ calculus.
