Royal Bank of Scotland's top investment banker has insisted he had resigned to take full responsibility for staff who rigged interest rates.
John Hourican, who is due to leave at the end of the month, said he had urged another senior executive not to fall on their swords over the abuses.
The comments came as Mr Hourican gave evidence to the Parliamentary Commission on Banking Standards.
Majority state-owned RBS was fined £390 million by US and UK regulators last week after evidence emerged of traders fixing the Libor interbank lending rate.
Some 21 staff have left or have been subject to disciplinary proceedings in the wake of the revelations but Mr Hourican is the only senior figure to depart, sacrificing millions of pounds in bonuses and share options.
He told the cross-party commission on Monday afternoon: "I do accept responsibility for the behaviour of our staff and therefore I accept responsibility for the failings that we have found.
"It is important that we do not talk about accepting responsibility and then not do so in our actions. That is why I have resigned."
Peter Nielsen, chief executive of RBS Group's markets division, said he also contemplated quitting.
"Of course I contemplated resigning," he said. "Indeed John and I talked about it. We talked about myself going instead of him."
Mr Hourican said: "This has been a long and considered discussion between myself and my chief executive Stephen Hester. It was my considered opinion that ... the stakeholders, the employees and indeed our customers would be better served by Peter remaining at the bank."