Bob Diamond has angrily rejected suggestions that he misled MPs over regulators' concerns about activities at Barclays.
The bank's former said the claims were "totally unfair and unfounded" - and indicated he was ready to appear before the Commons Treasury Select Committee again to defend his reputation.
The rejection of the claims came in a letter sent following an evidence session with Barclays chairman Marcus Agius.
"Having watched the committee's session today I was dismayed that you and some of your fellow committee members appeared to suggest that I was less than candid with the committee last week," he wrote.
"Any such suggestion would be totally unfair and unfounded."