Ken Lewis, Bank of America chief executive, faced aggressive questioning in US Congress yesterday over the circumstances surrounding the troubled takeover of Merrill Lynch last year.

Mr Lewis testified that he had no recollection of asking federal regulators in the chaotic weeks leading up to the Merrill Lynch deal for a letter that would protect him from shareholder lawsuits. He was then presented with an email from US Federal Reserve chairman Ben Bernanke alleging that Mr Lewis had asked for permission to say that the government had ordered him to complete the transaction.

In a congressional hearing, Mr Lewis also swatted away questions about why he did not disclose Merrill's mounting losses to his shareholders before they voted December 5 to approve the Merrill deal, or afterwards, when Merrill's escalating losses caused him to threaten the invocation of a “material adverse change” clause to scuttle the transaction.