LONDON – It's been a tense summer in the City of London as one bank after another has faced allegations of massive misbehavior.

Bankers in the British capital, which has for centuries been a center for global business, fear its reputation has been tarnished indelibly and that a heavy-handed regulatory crackdown is looming.

First came U.K. bank Barclays. Its chief executive, Bob Diamond, was forced to step down last month after U.S. and British authorities fined the bank $453 million for manipulating a key market interest rate. Other banks are being investigated for their part in the scandal.