Federalism and decentralisation offer political parties the opportunity to tailor their policy-seeking behaviour to different regional electorates. These electorates often possess different political preferences. However, the regional branches of nationwide parties must be careful not to dilute or even betray the core values of their party, for equally often they remain dependent on central support. This article studies the ensuing tension between regional deviations from national unity by analysing all vote recommendations of the four major Swiss parties on all 251 national referendums held between 1987 and 2015. Vote recommendations constitute an important guidance for voters. Analytically, the article focuses on the conditions of cantonal deviations from federal recommendations as a proxy for decentralised policy-seeking. It finds that ideological (socialism), temporal, vote-specific (distance to next election) as well as vote- and canton-specific factors (regional turnout and contestation) all influence party unity, with some effects varying by policy area and vote type.
