Ideology is widely seen as a powerful explanatory force of behaviour in collective decision-making. Yet, research on the Council of the European Union, the chief legislative body in the European Union, has only recently started to pay attention to ideology. We investigate to what extent formal position-taking can be explained by the ideological party affiliation of the governing parties. The focus is twofold. First, can aggregated coalition patterns be explained by ideological party affiliation? Second, do countries change coalition partners when there is a change of parties in government?