In this month's episode, Andrew talks to Lord Kerslake, former Head of the Home Civil Service, and Jo Casebourne from the Institute for Government about the impact new city region mayors will have on the political landscape of the UK. Andrew and his guests look at the changing role of MPs, and why some Westminster politicians are finding the prospect of being mayor attractive. Also touched on is the importance of mayoral influence as well as the powers handed over in devolution deals, whether there are too many politicians, and what Whitehall and Westminster should do in a more decentralised political environment.