Last week, the UK’s House of Commons was the scene of a debate about cotemporary anti-Semitism. It was an occasion when many Labour MPs, both Jewish and non-Jewish, related intensely personal stories about how they had been targeted by the purveyors of anti-Semitism.

Yet despite his formal public declarations against anti-Semitism, Jeremy Corbyn, the leader of the Labour party, absented himself for much of the debate and only turned up at the conclusion of the discussion when his close ally, Shadow Home Secretary Diane Abbott, responded.

Submerging the subject of anti-Semitism in her reply amidst a plethora of other Jewish issues (not least, bizarrely, a diversion into the education frameworks of the UK's ultra-Orthodox Jewish minority), Abbott left behind a raft of disgruntled Labour MPs.

Her mantra of meaningless phrases ("We in the Labour party take anti-Semitism very seriously...Twitter and Google need to act...Nothing is gained by accusing the Leader of Her Majesty’s Opposition of being an anti-Semite,"), repeated on so many previous occasions, was not a demonstration of naivety and nonchalance, but instead indicative of her party leader's worldview.

Corbyn's inability to understand those who consider anti-Semitism to be central as a narrative of politics and not incidental has ideological underpinnings.

In the far left’s political bubble, mainstream Jewish organisations become peripheral and unimportant, but marginal ones are publicly courted. This is why he chose to go to the alternative Jewdas Passover seder and stayed for four hours; why he wants miniscule, irrelevant groups like the Jewish Voice for Labour present at a roundtable discussion on anti-Semitism he has called with mainstream Jewish representative organizations; why he prefers groups on the far Left in Israel to the mainstream sister Labour party.

When it comes to normative party politics at Westminster, Corbyn insists that politicians listen to the voice of the masses – the Labour party membership, grassroots organisations, ordinary citizens.

With Jews, it is the exact opposite. Listening to "the people" does not count. There may well be justified criticism of the blunt-edged approach of the Board of Deputies of British Jews, but as several authoritative surveys have demonstrated, it broadly represents the Jewish community’s relationship to the State of Israel and its concern about anti-Semitism emanating from the Left.

Any shuffling of fringe Jewish groups with mainstream ones is not only a strategy of divide and rule, but also a means for Corbyn to pose as an eventual mediator between them.

He has also done this with the Israel-Palestine conflict, preaching peace, posing as an interlocutor, but in reality he is a supporter of one side – and one side only. Despite all rhetoric, he has never attempted any genuine mediation between Israelis and Palestinians during the last three decades.

Many British Jews feel propelled to support human rights internationally because of the Jewish historical experience: All injustices should be condemned. Several surveys have shown a majority of British Jews opposing the Israeli government's settlement drive in the West Bank.

In contrast Corbyn has perfected the expression of selective outrage. He therefore condemns Saudi Arabia for the war in Yemen, but remains silent on the protests against corruption in Iran. He praises Maduro’s Venezuela, but turns a blind eye to the hungry queuing for food, the use of force and the arrest of opposition figures.

Corbyn is capable of embracing a moral equivocation between oppressor and oppressed, just like Donald Trump. He is capable of empathy for the villain of the hour if their political credentials are sound in his eyes; indeed, Corbyn is then happy to portray them as a hero.

Corbyn admired Castro’s Cuba for lifting multitudes out of poverty and providing them with education and health care. But he facilitated this by demoting Castro’s silencing and imprisonment of dissenters to a lower rung of importance. Concern for human rights was relegated in the cause of the greater good.

This, in itself, is part of a wider world outlook on the far Left that places the totality of social and economic progress ahead of human rights and freedom of expression.

The right to express a different opinion, an alternative narrative, however, is important to intellectuals, writers, academics – and to Jews.

It was this display of double standards that began to push Jews out of the party. To paraphrase Karl Radek's pithy formulation from the 1930s about Stalin: "Moses took the Jews out of Egypt; Jeremy Corbyn takes them out of the Labour party."

Allied to the question of human rights, it is Corbyn’s Kremlin complex that compliments other blindnesses. His acrobatic apologetics for the Skripal poisoning in Salisbury and his evasion in holding Russia to account for the gassings in Syria are alarming.

In part, it arises from an affection for the good old days of the USSR. Many of his inner circle are formerly members of the pro-Kremlin faction of the Communist Party of Great Britain. Yet Lenin destroyed democratic socialism in Russia after 1917. The British Labour party would have been banned and its supporters sent to the gulag if it had arisen in Russia and not in the UK.

British Jews remember the Molotov-Ribbentrop Pact, when European Jews were considered by both Stalin and Hitler to be a disposable commodity. The supporters of the pact - Stalinists, Trotskyists and colonial nationalists - all had their vested interests during this period. They consisted of philosemites, anti-Semites and the indifferent. The common thread between them was that the fate of the Jews was nowhere near the top of their agenda.

In more recent times, British Jews have worked hard for the right of Soviet Jews to emigrate. Did Corbyn in the 1970s and 1980s support the right of Soviet Jews, not only to leave the USSR, but specifically to emigrate to Israel? Did he speak out about the Kremlin's harassment and persecution of human rights figures such as Andrei Sakharov?

At the root of all this is what it means to be a socialist, to be a member of the Left. For many non-Jewish Labour MPs who took part in the debate about anti-Semitism, the unspoken accusation is that Corbyn’s approach is lacking in socialist morality – and it is this that has caused the rift with Labour Party Jews and in a broader sense with the Jewish community itself.

That at its core is based on solidarity. Although the deputy leader of the Labour party, Tom Watson, made a point of sitting next to Jewish MPs in the House of Commons debate, there remains a perception that a chasm has opened up between the past and the present on matters that define the link between British Jews and socialism.

As Mike Gapes MP stated in a Commons debate about the UK’s air strike response to Assad’s use of chemical weapons, Labour has "a long-standing and noble tradition on these benches supporting humanitarian intervention." It was a direct attack on Corbyn’s refusal to commit to any kind of humanitarian intervention anywhere.

And MP John Mann said in the Commons anti-Semitism debate, with cold and eloquent fury, that they must "Stand in solidarity with the Jewish Members of Parliament under attack today."

Gapes, Mann and others in the parliamentary Labour party have publicly demonstrated that aligning themselves with Jews, valuing solidarity and condemning double standards is, for them, a badge of honor. It was the right thing to do – even if it meant criticizing the party leadership. For them, at least, the tragic past is not a foreign country.

Colin Shindler is an emeritus professor at SOAS, University of London