Sacha Baron Cohen, the Jewish comedian behind the Channel 4 character Ali G, has been branded "out of date, out of touch" and an embarrassment to the Jewish community.
In an open letter to the comic, the founders of Jewish.co.uk, the largest Jewish website in Britain, claims "the country's bored and the Jewish community is embarrassed" by his behaviour.
The letter follows Baron Cohen's four-letter outburst yesterday on the Radio 1 Breakfast Show.
"The character's original incarnation as a clueless interviewer taking on politicians and other figureheads was original and inventive, and the early material on C4's The 11 O'Clock Show and the spin-off TV show was very watchable," says the letter.
"However, somewhere in your psyche you have lost the plot and decided to exploit the situation by going for the lowest common denominator, which is mockery of people," it continues.
"In doing so, you have turned what was a fairly harmless character into something out of all proportion and, at times, insulting to everyone."
The letter said Ali G's "cheap insults and even cheaper material" were an insult to the Jewish community and bad for its relations with the wider UK population.
"At the end of the day, whether you like it or not, people see you as being Jewish and your attitude doesn't win the Jewish community any respect," it adds.
Jewish.co.uk is Britain's largest independent Jewish website and campaigns for greater diversity in the media.
In particular, it has thrown its weight behind a recent campaign to persuade broadcasters to stop pigeonholing Jewish broadcasting as religious.
Ali G's behaviour on Sara Cox's show yesterday earned Baron Cohen a stiff rebuke from the Radio 1 controller, Andy Parfitt, and outraged some media commentators.
In the course of a half-hour interview, the character used the word "motherfucker", suggested he had smuggled cannabis from Jamaica and insulted the two Pop Idol finalists.
He described Gareth Gates, who has a stammer, as "spasticated" and his rival, Will Young, as a "batty boy".
