They were the new laboratories where the UK would perform its biggest constitutional experiment in generations.

But twenty years on from the devolution of power to parliaments in Scotland, Wales and Northern Ireland, forces are on the move again and the UK constitution may be obliged to once more adapt to face new challenges ahead. Among them Brexit, a rising tide of both Scottish and Welsh nationalism and Northern Ireland’s continued inability to restore a power-sharing government.

As he visits the city of Derry-Londonderry – a city at the edge of the union on the Irish border – James Naughtie asks where the UK devolution project is now and where it may be headed.

Producer: Conor Garrett Show less