Last month, the Labour Party’s official explanation of why Jeremy Corbyn met with a Czechoslovak spy during the Cold War was that he failed to realise that this inquisitive representative of a Communist dictatorship was reporting back to his masters – something even Ken Livingstone managed to work out when he met with a similar “representative” of the Soviet Union at around the same time. In short, Labour’s defence for Corbyn’s actions is that he was, at best, too dim to know what he was doing when dealing with an agent of a hostile power.

Fast forward a few weeks, and it has emerged that Corbyn spent somewhere between one and two years as a member of a Facebook group called ‘Palestine Live’, where various members are alleged to have routinely posted anti-semitic tropes, neo-Nazi material, conspiracy theories accusing Israel of involvement in 9/11, et cetera. He became a member of the group in either 2013 or 2014 and is alleged to have left only after he became leader of the Labour Party.

As is now traditional, a series of excuses have promptly emerged.

Corbyn says that he was added to this group by someone else. That is perfectly possible – indeed Tory MPs have been dragged over the coals by Owen Jones and others for unknowingly being added to one unpleasant group or another.

Given that a Facebook user can be added to a group without opting to join it, this might be a reasonable defence (though one might still wonder whom it is that Corbyn knows who might have thought he would like to be added to a group which routinely featured anti-semitic bile), except for the fact that Corbyn not only remained a member for quite some time but actively participated on various threads, including liking posts, commenting, and interacting with other users. He is not alleged to have contributed or liked any racist content himself.

In the words of the Campaign Against Anti-Semitism:

‘Mr Corbyn allegedly stooped to personally comment in threads that include the term “Zio”, which even Baroness Chakrabarti’s whitewash report into antisemitism in the Labour Party condemned as an unacceptable term of abuse. He also collaborated with group members to organise an anti-Israel event that took place in his own office. Following the meeting on 3rd October 2017, in a thread contributed to by activists who overtly disseminate antisemitism, Mr Corbyn acknowledges those who organised the event, and apologises for his absence. In one comment he aligns himself with a group member who declares that “Israel is illegitimate” and in another he praises the controversial Dr Mads Gilbert, who has said of the 9/11 attacks: “the oppressed also have a moral right to attack the USA with any weapon they can come up with.”’

So while it might not have been his decision to join Palestine Live, we know that once he found himself there, Corbyn chose to stay and join the discussion.

But, but, but, the Opposition leader says, he might have been a member for quite some time and a participant in the discussion, but he didn’t know or notice that much of the group was an open sewer of racist filth:

“I have never trawled through the whole group. I have never read all the messages on it. Obviously, any anti-Semitic comment is wrong. Any anti-Semitism in any form is wrong…Had I seen it, of course, I would have challenged it straight away but I actually don’t spend all my time reading social media.”

Again, that’s possible – though to spot troubling signs in the group would not require him to have “read all the messages on it”, it would only require him to have noticed any of the apparently many instances of deeply unpleasant material that fellow group members were posting. Just as before, the best defence the Labour leader can mount is that he is extremely unobservant, even when very bad people are doing and saying very bad things on very sensitive subjects. Even if we’re being charitable, that isn’t a very good attribute in a would-be Prime Minister.

Oddly, John McDonnell has now added a further twist to the story. According to the Shadow Chancellor, Corbyn did become aware of the anti-semitic content in the group. He told Sky News this morning that:

“…when he discovered, and it was pointed out to him, that there were some people in it who were expressing anti-semitic views, he immediately came out of that. But also what he said…if any of those individuals are associated or members of the Labour Party, we will take firm action against them.”

That rather contradicts Corbyn’s own account of his total lack of any knowledge of the nature of this group or the material posted by a variety of its other members at any time. If McDonnell’s claim is true, it would also raise the question of why, if Corbyn left over anti-semitism in 2015 and promised to “take firm action” against those responsible, Labour is only acting against those people now, over two years later. The Leader of the Opposition’s office is reported to dispute McDonnell’s version of events.

I have not seen any evidence to suggest that Jeremy Corbyn himself is an anti-semite. Yet again, however, the best case scenario presented by his own defence is that he is extremely unobservant and managed to fail to notice the deeply unpleasant nature of people with whom he was mixing. One might have thought, given the fact that the taint of racism is well-known in many elements of the ‘pro-Palestinian’ movement, that he would be extra-vigilant in such a setting, but apparently not.

Just like before, Labour itself presents a defence which suggests Corbyn has a shocking lack of awareness or wariness about some of the people with whom his ideology leads him to mix. From meeting with a “diplomat” from Communist Czechoslovakia, when referring to “our friends from Hezbollah” and “friends from Hamas”, to doing paid presenting work for Iran’s propaganda channel, and now in the case of Palestine Live, this blindness to very bad people in close proximity is apparently a life-long affliction.