Discussion of how the UK can remain coherent as a multinational state needs to focus not on what powers might be given away to the regions and nations but on how to facilitate a sharing of power between different parts of the UK. This article examines how far programmes for constitutional reform, including the Welsh Senedd’s document Reforming our Union and the Labour Party’s A New Britain, have recognised the need for power-sharing in their discussion of matters like the reform of the House of Lords and the role of the Supreme Court. The conclusion is that current views of the sovereignty of the Westminster Parliament are incompatible with any meaningful constitutional reform. To change this would require a willingness to have constitutional arrangements much closer to those of the European Union, the very organisation which the UK decided in 2016 that it wanted to leave. It would also require seeing Northern Ireland less as a ‘troublesome province’ which needs to have its own form of government, but as an example of how progress can be made through power-sharing.