Ex-BHS boss Sir Philip Green has insisted he is "trying to find a solution" for the collapsed firm's pension fund and apologised to staff caught up in the "horrid story".
He acknowledged that selling the high street chain to Dominic Chappell's Retail Acquisitions firm was "a very bad choice" and he felt "badly let down".
But he lashed out at the parliamentary committees which produced a damning report into the collapse of the firm, insisting that it was a "predetermined and inaccurate output of a biased and unfair process".
Downing Street said the report produced by the MPs was "clearly concerning" and Prime Minister Theresa May would "lean lessons for the future" from the committees' inquiry.
Sir Philip is facing mounting pressure to be stripped of his knighthood and to rectify the black hole in the BHS pension fund after an excoriating joint report by two Commons select committees.
The two committees - Work and Pensions and Business, Innovation and Skills - accused the entrepreneur of seeking to blame anyone but himself for the firm's failure.
They said he has a "moral duty" to make a "large financial contribution" to the 20,000 pensioners facing substantial cuts to their benefits.
While the committees were damning about Mr Chappell, who bought BHS for £1, and the "directors, advisers and hangers-on" associated with the deal, they said ultimate responsibility lay with Sir Philip.
But the tycoon hit back, claiming the story of what happened was not being "fairly portrayed" and his lawyers demanded an apology from Frank Field, the chairman of the Work and Pensions Select Committee, accusing him of making defamatory comments.
Sir Philip said: "I have now carefully read the select committees' report and note their findings. I believe that the report is the predetermined and inaccurate output of a biased and unfair process.
"With the benefit of hindsight, clearly Retail Acquisitions and Mr Chappell were a very bad choice as purchaser on many fronts and I feel badly let down. Sadly, one cannot turn the clock back."
He said the sale of BHS was made "100% in good faith" and Retail Acquisitions and Mr Chappell had been provided with the "appropriate finance" - around £200 million of cash and assets - to take the firm forward.
Sir Philip added: "As I told the committees, I am trying to find a solution for the BHS pension and am continuing to work with the regulator to achieve an outcome.
"I am sad and sorry for all the BHS people caught up in this horrid story, but I do not believe that this story is being in any way fairly portrayed."
Mrs May's spokeswoman said the independent Honours Forfeiture Committee should be left to make a decision on his knighthood but reiterated the PM's desire to tackle corporate irresponsibility.
The spokeswoman added: "The report is clearly concerning.
"Action was already under way in response to the collapse of BHS.
"So the Insolvency Service have got their investigation, they have been asked to accelerate that; the Pensions Regulator is also looking at the issue.
"Of course it's important that those authorities carry out their work and get on with that as swiftly as possible."
Lawyers acting for Sir Philip wrote to Mr Field over his comments in a BBC Radio 4 Today programme interview.
Mr Field said Sir Philip is "much worse" than media mogul Robert Maxwell, who raided the pension pot of the Mirror Group newspaper business.
He described Sir Philip as a "Napoleon figure" floating around on his yacht, having "orchestrated" an "old-fashioned classical asset-stripping" which has put the jobs of 11,000 BHS workers at risk and left 22,000 pensioners with a risky future.
A letter from legal firm Schillings said Mr Field had made a "highly defamatory and completely false" allegation that Sir Philip had stolen money from the pension funds of the BHS and Arcadia retail groups.
Pointing out that Mr Field's comments were not protected by parliamentary privilege, the letter said: "In the circumstances, our client requires an immediate and fulsome apology in relation to the allegation."
In a hint at possible legal action, the letter said: "The other remedies to which our client is clearly entitled will very much depend on form and manner of your response."