It's official – mayors are so sexy that they have become superheroes.

After the LGiU think-tank proposed the introduction of a senate of directly-elected mayors charged with shaping Whitehall policy, Ed Hammond, a director at the Centre for Public Scrutiny, imagined the proposed senate not as a dry, bureaucratic committee – but instead as a panel of powered-up superheroes fighting the injustice of Whitehall diktat across local authority borders.