A leading Jewish charity is demanding an apology from Labour MP Harriet Harman after she repeated an offensive joke about the Holocaust on live TV.
But the former Labour deputy leader insisted that she recounted the joke in order to show that anti-Semitic humour was "no laughing matter".
In a discussion about unacceptable subjects for comedy on BBC1's This Week, Ms Harman said she had been branded "humourless" in the past for complaining about offensive jokes. And she went on to tell the joke as an example of the kind of material she objected to.
But her claim that presenter Andrew Neil would find the tasteless quip funny was rejected by the broadcaster, who turned his back on her and told her to "be quiet".
During a debate on the limits of acceptable humour, Ms Harman said: "I've long been accused of being a humourless feminist and I'll give you two examples that I protested about because they were offensive and hurtful.
"So, this was a Guy's Hospital rag magazine back in the day and people like Andrew say that these things are perfectly alright.
"Two jokes. One was 'How do you get 100 Jews into a Mini? One in the driver's seat and 99 in the ashtray'. That's not funny."
Cutting her short, Mr Neil responded: "We'll stop with that one example and we won't bother with the minute's silence that you would dare to think what I would think about that, because you have no knowledge of that at all."
As he turned to speak to another guest, the former Labour deputy leader attempted to interrupt in order to justify her decision to repeat the joke, only for Mr Neil to tell her: "Be quiet."
The broadcaster later explained his handling of the incident on Twitter, saying he was "appalled and even a little bit upset by what she said".
And the chief executive of the Jewish Leadership Council, Simon Johnson, demanded an apology from the Camberwell & Peckham MP for what he termed "a staggering error of judgment".
"I cannot recall being so disappointed in a politician," said Mr Johnson.
"Harriet Harman must surely know better than to repeat a vile Holocaust joke, irrespective of the point she was trying to make. She must apologise and do so quickly. It is a staggering error of judgement."
In a tweet released following Mr Johnson's call for an apology, Ms Harman said: "Anti-Semitic `jokes/banter' perpetuate discrimination & hatred. No laughing matter."
She linked the tweet to an excerpt from her autobiography A Woman's Work, in which she said that after complaining about the joke to Guy's Hospital and referring the matter to the Director for Public Prosecutions, she was accused of "over-reacting and being humourless" by a local newspaper. She said that Jewish community groups were "deeply appreciative when the hospital apologised".
Ms Harman's words also sparked condemnation from Twitter users, with some branding it "appalling" and one saying it was "unbelievable that any politician would say that on live TV".
The row came shortly after Mr Neil made a speech to a Holocaust Educational Trust dinner in which he warned of "the rise of anti-Semitism on the far left", which he said was "more dangerous than the knuckle-dragging right".