Former Cabinet minister Iain Duncan Smith "broke down and wept" when he recalled the plight of a young mother during a documentary on poverty, according to broadcaster Ian Hislop.
The Conservative, who dramatically quit as Work and Pensions Secretary over cuts to disability benefits, appeared to choke up as he told how the struggling teenage parent had "written off her life".
The interview with Mr Hislop was filmed in December last year, just months before the former party leader accused David Cameron and George Osborne of balancing the books on the backs of the poor as he stormed out of government.
Mr Duncan Smith said: "I remember visiting a lone parent a few years ago in an estate which had a very high number of single parents, young women, and when I sat and talked to her I sensed that she wanted to do something, she wanted to be better than her circumstances but she had no skills, she'd fallen out of school, she didn't know where to go.
"And, I remember leaving there thinking very simply, this is my daughter."
Mr Duncan Smith then apologised as he appeared to become emotional, telling Hislop: "I'm sorry I'm quite emotional about this ..."
He went on: "Nineteen years old," before his eyes welled up and his lip quivered.
After holding up his hand and pausing briefly, he continued: "My aspiration for my daughter was boundless. And here I'm sitting with a 19-year-old girl who had written off her life and had no aspiration and no self-worth. She was a product of a system. And my point was, what could I have done, what could we do to change her life?"
Private Eye editor Hislop, a team captain on the BBC's Have I Got News For You, said it had been an "extraordinary moment".
He told the Radio Times: "It was a curious thing. IDS actually broke down. He wept in front of me. It was a very extraordinary moment."
Asked if he comforted the Tory, he replied: "No, I just watched him cry. We're sitting in the Department for Work and Pensions talking about his desire to improve the lot of those without any privileges or start in life and he starts welling up."
Mr Duncan Smith's resignation in March sparked days of brutal Tory in-fighting after he launched an all-out attack on the Chancellor's "indefensible" Budget, claiming that cuts to disabled benefits in the financial package were "politically driven" and suggesting that Mr Osborne had abandoned the austerity principle of "we're all in this together".
:: Workers Or Shirkers? Ian Hislop's Victorian Benefits will be broadcast at 8pm on Thursday, April 7 on BBC Two.