Trading desks across the City of London have been awash with debate this morning: who might replace Bob Diamond? What does the future hold for Barclays' investment bank? And, perhaps a bigger question: to what extent does the departure of the bank's senior management set a precedent for other banks under investigation for Libor fixing?

Barclays announced this morning that chief executive Bob Diamond would step down, following in the footsteps of chairman Marcus Agius, who it was announced on Monday would step down as chairman as a result of the rate-rigging scandal that has engulfed the bank.