Nick Clegg has admitted he wanted to slap David Cameron on more than 20 occasions during their time in coalition.
In a lively interview on an anarchic late-night chat show, the Deputy Prime Minister also said Boris Johnson was more of a "twat" than a statesman.
During the appearance on The Last Leg, he was asked how many times in the last five years he had wanted to give the Prime Minister a slap. "A few times, yes, and, I think, likewise," he replied.
Pressed on whether it was more than 10 or 20 times, he said: "Oh, more than that."
The television appearance was soon trending on Twitter with the hashtag #cleggleg.
During a "showdown" with presenter Alex Brooker, who deployed a "bull**** buzzer" when he was unhappy with the quality of the Liberal Democrat leader's answers, Mr Clegg faced a barrage of tricky questions.
Asked if the London mayor was a statesman or a twat, he replied: "A bit more of the latter."
Clegg repeatedly refused to choose whether he preferred Cameron or Chancellor George Osborne.
Labour's Douglas Alexander, the shadow foreign secretary, talks "a lot of sense on Europe", he said.
But asked if he ever looked over at Labour and wished he had gone into coalition with it instead, Clegg said: "No, not very much".
"I just think they have both got it a bit wrong at the moment, actually. I think they are both lurching left and right."
After repeated prodding, Clegg admitted that, on a scale of one to 10, his angst over the decision to ditch his promise on tuition fees was a nine and a half.
Brooker turned the screw on the Lib Dem leader right from the start of the live show, warning him: "This ain't going to help your poll ratings."
When Clegg grabbed hold of the presenter's pocket handkerchief, Brooker, who has a disability, told him: "You've done enough bad things to the disabled."
In making a pitch to get the sceptical interviewer to cast a vote at the upcoming general election, the party leader said not voting would be like going into high street food chain Nando's, not putting in an order and then complaining if you were unhappy with what you were served.
Brooker later told the Deputy Prime Minister he had been a "good sport".
"I think I was kippered," Clegg said.