Remember Springtime for Hitler, the musical from hell in the immortal Mel Brooks movie The Producers? Well, British political activists are now promising us “Autumn for Jew-bashing.”In response to the Labour Party’s crisis over its anti-Jewish attitudes, a group called the Jewish Labour Movement is reportedly organizing a “rally against antisemitism” at the party’s annual conference next month. However, while Springtime for Hitler was comedy, Labour’s proposed spectacle is beyond satire.For the chorus line includes the Labour MP Naz Shah, the shadow Chancellor John McDonnell and the author of the party’s report on antisemitism Shami (now Baroness) Chakrabarti.Shah shared a graphic on her Twitter account which suggested all Israelis should be relocated to America. She has since grovellingly apologized and asked the Jewish community to educate her.McDonnell, who says party members with antisemitic views should be banned for life, shared a platform this week with Jackie Walker who claimed Jews were the “chief financiers of the sugar and slave trade.” He also once tabled a motion in Parliament claiming that “Israel tries to suppress criticism with false accusations of antisemitism.”As for Chakrabarti, dismay that her whitewash report signally failed to acknowledge the breadth and depth of Labour’s anti-Jewish attitudes turned into outrage and contempt when Corbyn rewarded her for her anodyne platitudes with a peerage and a likely shadow cabinet role.All that’s needed now is for Ken Livingstone to perform the goose-step with his finger resting on his top lip while repeating yet again his line that Hitler was a Zionist supporter and Labour’s “rally against antisemitism” will have brought the house down. The Jewish Labour Movement is trying to save the party from being tarred with the brush of Jew-baiting. This can’t be tolerated because, as everyone knows, Labour is anti-racist or it is nothing. So these attitudes have to be spun as some kind of aberration.Alas, they are not. Labour’s hard-left leader Jeremy Corbyn, who calls Hezbollah and Hamas his “friends” and can’t bring himself to pronounce Israel’s name, is blamed for legitimizing extremist attitudes toward Israel which have released the virus of antisemitism.Nevertheless, these attitudes have long been typical not just of the Corbynistas but of progressive opinion both inside and outside the Labour Party. Anti-Zionism and hatred of Israel are the default position on the Left.As the extremism researcher Dave Rich says in his new book, The Left’s Jewish Problem: Jeremy Corbyn, Israel and Anti-Semitism, for progressive people Israel has become “the epitome of Western domination, racism and colonialism, and the Palestinians have come to represent all victims of Western power and militarism.”Jew-hatred through the ages has unique characteristics: deranged lies and blood libels, double standards, obsessional malice, the imputation of a cosmic conspiracy of evil. Israel-hatred has exactly the same unique characteristics. Legitimate criticism it most certainly is not.Yet those on the soft Left deny any link between their Israel-bashing and antisemitism, which they blame entirely on Corbyn, the hard Left and the extreme Right.Rich’s book contains much that blows these self-serving progressive disavowals out of the water. He rightly identifies the New Left as the driving force behind liberal antisemitism, painting everything associated with the West as bad and everything to do with the developing world as good or justified.He also points out that it was not some Trotskyite grouping that turned the Left into an anti-Israel lynch mob but Britain’s Young Liberals who first libeled Israel with the utterly false claim of “apartheid.” Moreover this charge, which originated from the PLO in 1964 and thus predated the Six Day War, was used by the Young Liberals to condemn as illegitimate not the settlers but the existence of Israel itself. Not everyone who bashes Israel in this way is an antisemite. It is possible to be against antisemitism but nevertheless subscribe out of sheer ignorance to a picture of Israel based entirely on lies.There is, nevertheless, a distinction between the teller and the tale. Those who demonize Israel, both Jew and non-Jew, are expressing an irrational hostility to the Jewish people or the concept of Jewish peoplehood, all of which is a form of anti-Jewish discourse.No one ever calls mainstream progressive opinion to account for these vicious attitudes. No one ever calls out left-wing “anti-racists” for supporting a Palestinian agenda which rests on Jew-hating libels and caricatures straight out of the Nazi playbook.What was the response when the former Labour foreign secretary, Jack Straw, reportedly told a meeting in 2013 that “unlimited” funds available to US Jewish organizations were the greatest obstacle to peace between Israel and the Arabs? Silence.To eradicate antisemitism from the Labour Party would force left-wingers to do something they find simply impossible: face up honestly to the truth about themselves.They ignore the antisemitism in left-wing thinking because to admit it would knock the political ground from under their feet. This is because they believe that leftism is virtue incarnate and antisemitism only ever occurs on the Right. It is impossible for them to admit they support an anti-Jewish agenda, even in ignorance, because if the doctrine of their own moral perfection is smashed the whole progressive agenda goes smash too.It’s safest, therefore, to pin antisemitism on the extremes: the far Right and the hard Left. When Labour’s “moderates” attack Corbyn, however, they are in fact holding up a mirror to themselves.Melanie Phillips is a columnist for The Times (UK).