Large coalition governments, including all relevant parties, are at the heart of the consociational model of Swiss democracy. Until the 1990s, this model was characterised as "voluntary proportional". It was based on a stable cooperation of two main blocs of political parties, and on elite-driven agreements on all-inclusive government formulas. Despite growing competition in governmental elections, all-party coalitions have survived in most cantons. This article explains that the political minority could keep and even improve its representation, as a consequence of the divisions in the political majority. While right-wing parties hold the majority in almost all Swiss cantons and at the federal level, they are no longer sufficiently cohesive to control the elections. As a consequence, elections have become more uncertain, and political minorities can capitalise on this in order to win seats. Empirically, this paper investigates elections for Swiss cantonal governments in the period 1971-2011. It combines data on the unity of political blocs with data on government formation. To measure the political unity of the blocs, the paper introduces a novel measure based on the voting recommendations issued by cantonal parties on the occasion of national referendums.