The chairman of Barclays Bank is reported to be on the brink of stepping down as the row intensifies over the Libor rate-fixing scandal.
Reports said Marcus Agius was about to leave the embattled bank, which declined to comment on the suggestions.
BBC business editor Robert Peston said: "Today Mr Agius has told his colleagues on the Barclays board that he will be going. It's not wholly unexpected. Mr Agius was first in the firing line as far as shareholders were concerned, they've been thinking for some time that Barclays might need a new chairman, he's been in the job for six years next year."
The development came after Business Secretary Vince Cable backed calls for a criminal investigation into bankers involved in the affair. The Liberal Democrat Cabinet minister said the public could not understand why the perpetrators of "what looks like a conspiracy" were allowed to "just walk away".
The potential for prosecutions arising from the scandal has been downplayed by Treasury sources who point out that there are no criminal sanctions in place for manipulating the inter-bank lending rate, known as Libor.
The Independent later claimed it had obtained a memo relating to a meeting held on Thursday between Mr Diamond and staff at another bank which suggested he was relatively upbeat about the longer term - but that things would get worse before they got better.
The memo, from analysts at investment bank Morgan Stanley, said Mr Diamond feared the scandal would lead to "more political intervention" and reinforce the "bad caricature" of the industry. According to the memo,
Mr Diamond said he expected pressure on the industry would recede once reforms had been put in place to deal with the question of what to do with banks deemed "too big to fail".
Under the heading "Political and Regulatory Aftershocks", the memo said: "[He] fears more political intervention. Thinks political and regulatory pressure will fade as the too-big-to-fail question is addressed... but that is for the longer term and things get worse before better."
Mr Cable's intervention came as it emerged that taxpayer-backed RBS has sacked four staff over their alleged role in the Libor-fixing scandal. It is understood they were traders Paul White and Neil Danziger, investment adviser Andrew Hamilton and Tan Chi Min, who used to work for RBS in Singapore. The bank declined to comment on the matter.