Is Jonathan Arkush right? Should the Board of Deputies meet Jeremy Corbyn ? Or are the critics right to argue that there is nothing to discuss and nothing to be gained?

Let me start by sharing an experience. Over the past two weeks, I have been fighting Holocaust deniers on Twitter. It started with my challenging a man who referred to the "holohoax". This man has tens of thousands of followers and some of them started tweeting me back.

None were put off by his holocaust denial, I'm afraid. They just argued that there was nothing wrong with questioning the numbers, as they put it.

I began to notice a pattern. These tweeters would, in their potted biographies, claim to be "humanitarians" or "citizens of the world". They would say that they were green, and vegetarians, and hate right wingers. And hate Zionists, too, of course. The root of their Holocaust denial, or tolerance of it, was their idea that Israel is a colonialist occupying force. The idea that it was needed as a refuge for Jews fleeing persecution thus needs to be countered. And this leads them straight to a conspiracy theory about the Holocaust.

This stuff would be shocking from anyone, but seems, somehow, especially distressing from people who proclaim themselves compassionate and think of themselves as champions of the oppressed. But, unfortunately, I fear we have to face the fact that, in the west, these sorts of people now constitute the main source of Jew hatred.

Which brings me to Jeremy Corbyn.

Nothing, I think, would be further from the mind of Jeremy Corbyn than to deny the Holocaust. I am as certain as I can be that he personally rejects such conspiracy thinking. Yet two conditions have to be added to this.

The first is that his rise has brought with it antisemitism. The rock singer Ian McNabb, for instance, tweeted this week as follows: "Jeremy Corbyn. What happens when a decent man who is not owned by Rothschild Zionists rises to the top in politics". Owned by Rothschild Zionists. He really said that.

The second is that Mr Corbyn has not been as careful as one might hope with his associates . He has not in the past been averse to sharing platforms with people whose social views - including Holocaust denial - do not attain the highest standards. But he denies being aware of their views and certainly says he doesn't approve of them. So what is the right approach. Arkush's or that of the critics? I think Arkush is correct. To start with, it's not our job to choose the Leader of the Opposition. As a community, we need to respect the Labour Party's right to do that. The reasons for refusing to deal with an elected MP and leader of a major political party would need to be overwhelmingly strong.

It would also be a tactical error. Mr Corbyn is keen to have better relations with the Jewish community. He wants this for political reasons (although these are not overwhelming) and he wants it because he doesn't like being thought illiberal or against any community. In personal contacts, he is rather gentle and conciliatory. It is part of his character and in some ways a strength. But it is also a weakness.

A direct personal encounter could make Mr Corbyn understand how bad Holocaust denial, in particular, has become on the international left and recruit him to a robust response. It could make him a little more careful about the platforms he appears on and the people he encourages. It could make him hesitate before lending his credibility to Jew haters who might later be exposed as such.

Such hesitation would be a gain. And if we were unable to induce it, at least we would better know where we stand.

Daniel Finkelstein is associate editor of The Times