The Barclays affair may lack the spice of some recent banking scandals, involving as it does the rather dry “crime” of misreporting interest rates. But few have shone such an unsparing light on the rotten heart of the financial system.

Behind the technical language, what has been exposed by British and American regulators is nothing less than a long-running confidence trick played on the public for personal and institutional advantage. Putting that right will take more than a few paltry acts of contrition by Barclays’ bosses and a bit of hand-wringing from the authorities.

The bankers involved have betrayed an important public trust – that of keeping an accurate public record of the key market rates that are used to value contracts worth trillions of dollars. They did so to make money and to conceal from the wider world their true cost of borrowing. This was market-rigging on a grand scale. It is hard to think of anything more damning – or more corrosive of the reputation of capitalism.