Abstract Choosing coalition partners is not only about size but also revolves around policy. Although this claim is undisputed at the national and regional levels, the role of ideology in local coalition formation remains contested. This study examines how policy positions and issue salience influence coalition formation after two consecutive elections in 30 municipalities in the Belgian region of Flanders. We apply for the first time the concept of preference tangentiality – the degree to which parties prioritize different policy areas – to the analysis of coalitions at the local level. Our findings reveal that ideological proximity increases parties’ likelihood of forming coalitions, but only to the extent that they do not cooperate with the far-right Vlaams Belang. While preference tangentiality alone does not predict local coalition formation, it becomes important for ideologically coherent executives in which parties must differentiate themselves from their coalition partners. These findings enhance our understanding of policy-related factors in coalition formation at the local level.
Reuse et al. (2026) studied this question.