Despite sustained public demand for parties to act, the environment has been subject to limited issue salience in UK state-wide elections. This article uses qualitative and quantitative methods to explore party politicisation of the environment in regional elections 1998–2011. Contrary to earlier suggestions, the present findings indicate that multi-level systems may facilitate increasing environmental issue salience at the meso level. In part this is a function of nationalist parties' prioritisation of the environment. Overall, electoral discourse is shown to have a key formative role in driving policy divergence owing to inter-polity and inter/intra-party contrasts in salience and framing. From a normative perspective this suggests that the pluralising effect of (quasi-)federalism has the potential to foster greater responsiveness in party programmes through enhanced choice for the environmental issue public. This is an outcome of the expansion of electoral politics following state decentralisation and associated party competition to advance distinctive proposals over rivals.