One of the most enduring debates about decentralised forms of government has been the tension between equity and diversity. Postwar conceptions of the welfare state have stressed the principle of state-wide equality of citizens’ rights of access to public services. But federal, regional and devolved forms of government enable territorially differentiated packages of public services. And decentralised government has become significantly more widespread and more powerful over the last 30 years (Marks et al, 2008). The scope for tension between the equity goals of the welfare state and the diversity of outcomes that decentralised government brings has grown.

This chapter explores this tension in the case of the UK a decade or so on from the introduction of devolved government in Scotland, Wales and Northern Ireland. Its focus is twofold. It explores how ordinary citizens negotiate the additional opportunities for political participation that devolution has brought; and it asks whether devolution has prompted any rethinking of the appropriate territorial scale – devolved or UK-wide – at which citizens prefer to express social solidarity with one another. It approaches these questions by drawing on, and developing, T.H. Marshall's (1950 [1992]) conception of citizenship rights, in particular his understanding of citizenship as composed not just of civil and political rights, but also social rights. Marshall has increasingly become conscripted into debates about whether equitable, national social rights of citizenship, as institutionalised in the postwar welfare state, are eroded by the policy diversity implied by decentralised government.

The chapter starts with a reflection on Marshall's conception of how the content of citizenship evolves over time, as different forms of citizenship rights interact and ‘spill over’ into one another. Marshall's focus was on such interactions at a national scale. The discussion here takes forward the logic of Marshall's arguments, but extends them to the regional scale. Drawing on recent contributions both to comparative analysis and to discussions about the tensions of welfare equity and political diversity in post-devolution UK, it sets out a number of interpretations of how political and social rights might interact with each other across the UK's national (that is, UK-wide) and regional (that is, devolved) scales.