The time has come for the City of London to celebrate a new Magna Carta. Next June marks 800 years since King John signed the original Great Charter, the City’s own copy of which played a starring role in last week’s Lord Mayor’s Show.

Now we need a new one. This time it would be a charter not between a grasping monarch and his people (or rather his barons) but between a breed that sometimes rivals King John's disdain for the law - the bankers - and their customers.