It is not often you hear bankers or politicians questioning the status of London or New York as financial centres. These are the established, cocky hubs of the financial world.

Frankfurt is different. These days, with thousands of jobs shed by the big banks, the tally of serious domestic investors down to half a dozen and a stock exchange humbled by a failed takeover attempt of the London Stock Exchange, the city seems increasingly unsure of itself, almost desperate to prove its worth.