The party issued the refusal when the shadow foreign minister, John McDonnell, faced questions about his support for the creation of a controversial anti-Zionist group in 2008.
The incidents have directly dragged the Labor leader and the de facto deputy into the lineage of anti-Semitism that threatens to tear the Labor Party apart.
On Wednesday, Corbyn apologized for attending once a "protest event" on International Holocaust Day, and Labor MPs spearheaded the condemnation.
Meanwhile, a member of the governing body of the Labor Party saw the elimination of support for re-election after it was registered by calling members of the Jewish community "Trump fanatics."
Later, a speech was delivered by Corbyn at a rally outside parliament in 2010, when he compared the blockade of Gaza with the sieges of Leningrad and Stalingrad in World War II.
He told the crowd: "I was in Gaza three months ago, I saw the mortar shells that had gone through the school buildings, the UN buildings destroyed, the schools burned, the houses in ruins, the lives destroyed, the people imprisoned, the psychological damage to an entire generation that has been incarcerated during the time that the siege of Leningrad and Stalingrad took place. "
A Labor spokesman told The Guardian: "Jeremy was not comparing the actions of Nazis and Israelis, but the conditions of the civilian populations in the cities besieged in time of war."
The event came six months after Mr. Corbyn organized a Holocaust Remembrance Day event that said that the speakers compared Israel's actions in Gaza with the Hitler regime.
"Jeremy was not comparing the actions of the Nazis and the Israelis, but the conditions of the civilian populations in the cities besieged in time of war"
The Labor leader acknowledged that he had appeared with people "whose views he completely rejected" and apologized for the "worries and anxiety" he caused.
McDonnell said on Thursday he wanted the party's approach to anti-Semitism to be resolved soon, adding: "It shocked us deeply."
However, he also faced questions about his support for the controversial Jewish international anti-Zionist network (IJAN), whose creation he endorsed in a 2008 motion by Commons.
The IJAN letter asks potential members if they "feel angry and sad that the holocaust against the Jewish people is being used to perpetrate other atrocities."
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A spokesman for the Labor Party said McDonnell "was welcoming the creation of an organization that represented an important branch of the radical Jewish political campaign."
"Of course he did not endorse or endorse all the language and opinions expressed in his statutes," the spokesperson added.
The early day motion, of which McDonnell was the principal signer, endorsed "the launch of the International Jewish Anti-Zionist Network and its Founding Charter."
According to reports, critics said the letter violates the definition of anti-Semitism of the International Alliance for the Memory of the Holocaust (IHRA).
The reluctance of the Labor leadership to adopt the definition of IHRA and its examples has become a high point in the dispute over anti-Semitism in the party.
Meanwhile, the Campaign Against Antisemitism (CAA) has referred workers to the Equality and Human Rights Commission.
The CAA has also filed a complaint with the party regarding the comments of Mr. Corbyn and his host of the 2010 event.
The president of the campaign, Gideon Falter, said: "Jeremy Corbyn has spent his political career sharing scenarios with anti-Semites and honoring them.
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"This apology sounds completely hollow, Mr. Corbyn did not just attend the event, he chaired it, and in response to criticism from the Jewish community in 2010, he did not apologize."
On Wednesday, a key group of Jeremy Corbyn's support campaign withdrew his support for a member seeking re-election to the National Labor Executive Committee after his "deeply insensitive" comments about the Jews.
Momentum added that it was "inappropriate" for Peter Willsman to call some members of the Jewish community "Trump fans" and also suggested that they were "inventing" problems about anti-Semitism in the party.
The grassroots campaign group also emphasized the need to recognize the "anger and discomfort" felt within the British Jewish community by reaffirming their commitment to "eradicate" anti-Semitism in the Labor Party and in society.