David Petraeus has admitted that he "screwed up terribly" by having an affair with his biographer, as he prepared to emerge from hiding to be questioned by US congressmen today.
The fallen CIA director said he regretted the liaison with Paula Broadwell that has thrown America's national security establishment into crisis, but insisted that he did not pass her classified intelligence.
Describing his wife, Holly, as "far better than he deserves", Mr Petraeus said in an off-camera conversation with a television journalist that he was guilty of a "personal failing" and had "engaged in something dishonourable".
"He sought to do the honourable thing in response," recounted Kyra Phillips, a reporter for HLN, "and that was to come forward. He was very clear that he screwed up terribly."
Mr Petraeus, who has not been seen in public since his resignation a week ago, is due to testify early this morning to congressmen investigating the September 11 attack on the US consulate in Benghazi, Libya.
The retired four-star general rejected conspiracy theories that his downfall had been engineered to somehow prevent him from disclosing information on the attack that could be damaging to President Barack Obama.
"He said this has nothing to do with Benghazi, and he wants to testify," said Ms Phillips.
"He will testify."
The 7.30am hearing, by the House intelligence committee, will be closed to the public.
Senior Republicans, including Senator John McCain, accuse the Obama administration of failing to provide adequate consular security despite requests from Ambassador Chris Stevens, who was killed in the attack.
They also allege that the White House deliberately misled the public by stating initially that the attack had spilled over from a chaotic protest against an anti-Islamic American film, when in fact it appears to have been a co-ordinated terrorist strike by jihadists.
Fears that Mr Petraeus had briefed Mrs Broadwell on secret details of the Benghazi assault were sparked by the emergence of footage of a speech in which she said the attackers had been attempting to spring Libyan radicals from a makeshift CIA jail.
Authorities said this was not true and that she had misinterpreted media reports.
Mr Petraeus reiterated assurances given by Mr Obama earlier this week "that he has never passed classified information to Paula Broadwell".
Mr Petraeus (60) resigned last Friday after confessing to an affair with Mrs Broadwell, a 40-year-old author and former military officer, which was being investigated by agents from the FBI.
The inquiry was prompted after Jill Kelley, a 37-year-old "social liaison" for the US military in Florida, received anonymous emails warning her to stay away from Mr Petraeus, whom she says was a friend.
Mrs Kelley's complaint to the FBI led agents to email accounts owned by Ms Broadwell, and to the discovery that she was engaged in a relationship with Mr Petraeus. (© Daily Telegraph London)