Former HBOS chief executive Sir James Crosby has stepped down as non-executive director of catering firm Compass Group and said he wants to be stripped of his knighthood in the light of last week's scathing report into the bank's collapse.
Sir James, who also said he was to give up 30% of his £580,000-a-year pension, still holds the knighthood as he cannot himself renounce the title.
The bank's former boss was given a knighthood after leaving HBOS in 2006, but said he believed "it is right that I should now ask the appropriate authorities to take the necessary steps for its removal".
Sir James, who stepped down from his role with private equity firm Bridgepoint on Friday, said he was "deeply sorry" for what happened at HBOS and the "ensuing consequences" for the bailed-out bank's staff, shareholders and taxpayers.
For the knighthood to be withdrawn, the Honours Forfeiture Committee has to make a recommendation to the Prime Minister, who then passes it on to the Queen for a decision. The committee meets on an ad-hoc basis when a request is made for an honour to be reviewed - a request anyone can make.
A Cabinet Office source said: "If he was to write to the Forfeiture Committee himself, the committee would take that very seriously."
The Parliamentary Commission on Banking Standards claimed in Friday's report that Sir James was the "architect of the strategy that set the course for disaster" and held primary responsibility for the collapse along with former chairman Lord Stevenson and fellow chief executive Andy Hornby.
Their "toxic" misjudgments were blamed for the bank's downfall and £20.5 billion taxpayer bailout at the height of the financial crisis and the commission said they should not be allowed to work in the financial sector again. Sir James said the report made for "very chastening reading".
He added: "Although I stood down as CEO of HBOS in 2006, some three years before it was taken over by Lloyds, I have never sought to disassociate myself from what has happened. I would therefore like to repeat ... what I said when I appeared in public before the Commission in December; namely that I am deeply sorry for what happened at HBOS."
His decision to forgo 30% of his pension will still leave him with an annual payout worth £406,000. He said he was also standing down from his voluntary position as a trustee of Cancer Research UK with "great personal sadness".