So, I had that anti-Semite in the back of my cab. And you know what I said to him? Do yah? Do yah? Nah, I don’t remember either. Tchaboom! I’m here all week.

We know — at least we ought to know, because he never tires of telling us — that the writer and comedian David Baddiel is, at the very kindest, agnostic when it comes to Israel.

Actually, it’s much more acute than that. He is not remotely interested in Israel or in anything it stands for. Baddiel’s Twitter profile describes himself simply: “Jew”.

By that he means someone who shares a cultural and social history with many of us, and at the same time is painfully aware that the Nazis would not have made a subtle differentiation between those who love Israel and those who are simply indifferent to it. Or those who are religiously observant and those who are not.

As far as Baddiel is concerned, as I understand him, a Jew is a Jew is a Jew.

Which means, accordingly, that anti-Semitism is anti-Semitism is anti-Semitism, dress it up how you may, put lipstick on it, whatever you like. It is racism, pure and simple, and Baddiel, whose mother was a Holocaust survivor, has been at the forefront of attacking its proponents wherever he can.

A couple of weeks ago Baddiel took part in a BBC comedy chat show, Frankie Boyle’s New World Order, in which he, Boyle, and three women actors and comedians spoke interestingly about anti-Semitism and how it manifests itself in political life.

Boyle later complained that references to Israeli “apartheid” had been edited out of the show without reference to him. But then, overwhelmed by being attacked on social media, he declared: “I’ve had from literally hundreds of people, that anti-Semitism in Britain should not be discussed while Israel commits war crimes. The idea that Jewish people have collective responsibility for Israel is racist”.

So far, so depressingly predictable.

But matters took a weird turn this week after another BBC programme, Tracey Breaks The News, in which the comic actor Tracey Ullman assumed the guise of none other than Jeremy Corbyn to make a pointed joke about the company that the Labour leader keeps.

In her sketch, Ullman, queuing for an airport taxi, is first directly snubbed by a Jewish man who assails Corbyn for his behaviour, and then refuses to shake his hand. Eventually the Corbyn character is driven away in a cab by “Ismail, from Hamas”, who reminds him of how they had tea together at the House of Commons.

Watch the sketch here:

I can’t pretend it’s wildly funny, but it’s not often that Corbyn gets mocked on TV. And the Corbynistas went wild.

And here’s where the conspiracy theories went deranged. An actor and writer called “Dylan Strain” flat-out announced on Twitter that David Baddiel had written this sketch. He hadn’t; nine writers, not one of whom, as far as I know, is Jewish, are credited with the work on the show.

As the writer Linda Grant summed up: “Jeremy Corbyn’s supporters are currently attacking Baddiel for writing a Tracey Ullman sketch about Corbyn, which he didn’t write, but must have done because he’s a Zionist ( he isn’t.)” Oh, and quite a lot of the loonies insisted that Ullman herself is Jewish, which she isn’t.

Strain backtracked and claimed he was being sarcastic because of Baddiel’s earlier appearance on the Boyle show. It didn’t look like sarcasm to me, or Baddiel, or indeed the mad Corbynistas.

In the absence of a statement from the Board of Deputies denouncing something, I’d like to thank Tracey Ullman for proving a point. And to praise David Baddiel for confronting anti-Semitism. And to note, as Chaplin and Mel Brooks amply demonstrated, that nothing deflates pomposity like being laughed at.