Jeremy Corbyn has been accused, once again, of anti-Semitism; this time for remarks he made at the Britain’s Legacy in Palestine Conference in January 2013.

Somewhat sceptical at the initial report of this incident coming from the Daily Mail, I decided to watch the entire 50-minute video of his and various others’ speeches from the conference.

Here’s what I have concluded:

For his part, shadow chancellor John McDonnell claimed on the Today show that the comments had been “taken out of context”, appealing to the Labour leader’s attempts through the years to “secure peace”.

In “that context,” said McDonnell, “Jeremy has devoted his life, so I think to take expressions out of context in that way are not helping.”

I agree with McDonnell that, as with any accusation of racism, is important to know the full context. Indeed, the biggest irony over the debate surrounding the International Holocaust Remembrance Alliance’s definition of antisemitism versus the Labour NEC’s version, is that only the IHRA definition makes clear that its examples of antisemitism must only be considered “taking into account the overall context”.

The focus of this conference was on the then-upcoming centenary of the Balfour Declaration, which was issued in 1917. Of the speeches, which are generally low-key and academic in tone, I recommend that of the Palestinian ambassador, Dr Manuel Hassasian, which begins three minutes in to the video. He is eloquent and dignified, and sets out well the Palestinian grievances over the declaration. He makes no mention of British Zionists.

Then, at seven minutes and 20 seconds, comes Corbyn. The controversial part is from eight minutes and 25 seconds. Here’s what he says:

“The other evening we had a meeting in parliament in which Manuel [the Palestinian ambassador] made an incredibly powerful and passionate and effective speech about the history of Palestine and the rights of the Palestinian people. This was dutifully recorded by the – the thankfully silent Zionists who were in the audience on that occasion, and then came up and berated him afterwards for what he had said. They clearly have two problems: one is they don’t want to study history and secondly having lived in this country for a very long time, probably all their lives, they don’t understand English irony either. They needed two lessons, which we could perhaps help them with.”

People make much of Corbyn associating with people who espouse conspiracy theories and anti-Semitism. Even in this 50-minute video, Corbyn is immediately followed by Stephen Sizer, an Anglican vicar who, in the months leading up to the conference, was in trouble for sharing anti-Semitic links – and whom Corbyn has defended.

But leaving aside the “guilt by association” point, what strikes me about this video is that amongst the many speakers of varying nationalities and backgrounds, Corbyn is the one who lowers the tone and makes comments about “thankfully silent Zionists”. And he is angry when he says it.

The comments themselves are sarcastic, petulant and, in my view, casually racist. Corbyn is comparing “Manuel”, the Palestinian ambassador who had just spoken very well, to the “Zionists”, who “having lived in this country a very long time, probably all their lives, they don’t understand English irony”. It is said with anger, and as though he is trying to prove something to the audience.

His comments have obviously racist undertones. The idea that British Zionists are not really British, that they are interlopers here, that they don’t “get” English irony, is a classic trope. I am not sure whether he is referring to all British Jews or not, or even all Zionists, but it doesn’t really matter as it is such an incautious comment. If an employer made these comments about a Jewish employee, I expect the employee would have a strong case for harassment on grounds of race. If you doubt this, try reading the above excerpt and replacing “Zionists” with “blacks” and see whether you see racism.

I thought I would watch the video and find a hostile environment in which Corbyn was just fitting in. But he is the only one, on this 50-minute video, to bring any animus at all. He lowers the tone from the eloquence of the others.

Finally, having considered this and listened to many views from social media, there is probably something in the point that Corbyn may, in his own mind, have only been focussing on the small group of Jewish activists who attend pro-Palestinian events, ask difficult questions and write critical blogs afterwards. But the video is evidence that his obvious anger at those men, undoubtedly bound up in his passionate support for Palestine, has spilled over into a stream of anti-Semitism that classes Jews as aliens and un-British. This is, ironically, an object lesson in why the IHRA definition of modern anti-Semitism includes references to Israel and Zionism.

In future, Corbyn would do well to follow the words in the NEC’s draft definition of anti-Semitism: “Labour Party members should only use the term `Zionist’ advisedly, carefully and never euphemistically or as part of personal abuse”.