On the face of it, this proposal from the New Local Government Network (NLGN) makes sense. In summary, they want to replace the Greater London Assembly with a council made up of the leaders of London's boroughs.
I'd go one step further and get rid of the elected mayor as well - and just have a regional assembly made up of nominated councillors, who in turn nominate a mayor.
This would not only be a very good idea in principle for London. It would also provide a template for regional government throughout the rest of the UK. You could sack all of those MLAs in Northern Ireland, the MSPs and the WAMs. And you could set up regional assemblies where they don't really sit properly everywhere else.
It would mean that councillors would have more power, and people would have a reason to care about which councillors they elect. And it would allow you to establish real regional government throughout the UK - without having to have a referendum.
In the worst case - if you have to have a referendum, it would be winnable, because the question would be framed in the kind of terms that would appeal to the fuckwits who usually advocate referendums.
People would be asked if they want to sack elected politicians.