"Do you want to know my toilet habits?" Lord Patten asked during a bad tempered exchange with Tory MP Philip Davies on Tuesday.
Appearing before the Commons culture, media and sport committee, the chairman of the BBC Trust got into a series of tense arguments with Davies, who wanted to know exactly how many days he spent on his BBC job compared to his other roles.
Davies has already said Patten should be forced out of the BBC in the wake of the crisis that began with the revelations about Jimmy Savile's abuse of children.
Patten suggested Davies had been opposed to his appointment in 2011 in the first place and suggested the Tory MP was using the committee hearing to push a wider anti-BBC agenda.
"If you think I am going to do a diary for you in order to satisfy some populist pursuit of somebody you didn't want to run an organisation which you don't want to exist, you are kidding yourself," he said.
"I think it's a thoroughly impertinent question. I think you're entitled to know how much time I'm spending, I think you're entitled to put down freedom of information requests for how many days I spend in the office, or how many days I spend doing other things.
He added: "Do you want to know my toilet habits? What else do you want to know?"
Davies fought the apparent slapdown, saying: "Given you have been presiding over a shambles at the BBC I think it's perfectly reasonable to say have you been actually putting in the hours, putting in the yard as you should have been as chairman of the BBC Trust."
Patten who was chairman of the Tory party in the early 1990s, also took the opportunity to take a swipe at his right-wing rival by reminding him that the last time the Tories won a general election was in 1992 - when he was chairman.
And he mounted a strong defence of the BBC, comparing it favourably to foreign broadcasters. Patten admitted the corporation could be "smug and complacent" but said most of the time it represented many of the best qualities of the country.
"Anyone who rubbishes the BBC should be forced to watch Italian, French or American TV for a week or so," he said.
"If you want Italian TV with 'bunga bunga' and the prime minister deciding who should run it then so be it."
Addressing the botched Newsnight report that wrongly implicated Lord McAlpine in a paedophile ring, Patten rejected the suggestion that BBC journalists had been blinded by their desire to connect a Thatcherite Tory politician to a scandal for political reasons.
"When I look at the ranks of cabinet or ranks of government advisers I don't buy the story that the BBC is a hotbed of Trots," he said.
Patten may have been referring to the decision of former BBC employees Craig Oliver and Thea Rogers to take a jobs working for David Cameron and George Osborne.