On the cusp of a major vote by Britain’s Labour Party over the definition of anti-Semitism, two former Labour prime ministers have issued stark warnings about growing anti-Semitism in the party under its current leader, Jeremy Corbyn 

Prime ministers Tony Blair and his successor Gordon Brown have both publicly rebuked Corbyn in recent days. Their statements come as the Labour’s national executive committee (NEC) prepares to vote Tuesday over whether or not to adopt the International Holocaust Remembrance Alliance (IHRA) definition of anti-Semitism. In Labor proceedings earlier this year, objections were made to language in the IHRA criteria that critics claimed would stifle criticism of Israel by, for instance, classifying accusations of double loyalty against British citizens as anti-Semitic.

In an interview published over the weekend in Euronews, Blair discussed the controversy over the NEC vote in the context of broader issues of anti-Semitism in Labour. “This has been a truly shameful episode for the Labour Party and it’s causing real difficulties for those of us who stay in the Labour Party and want to see it come back to sense,” the former prime minister said. Adding, “to see a situation in which the Jewish community in this country feel really alienated and worried and anxious and that’s a terrible thing to have done.”

Over the weekend, Blair’s successor Gordon Brown appeared at the Jewish Labour Movement conference where his impassioned speech calling on the party to accept the IHRA definition “unanimously, unequivocally, and immediately” was met with a standing ovation from the crowd.

The simmering conflict between Corbyn’s wing of the labor party and mainline British Jewish organizations began when the left wing leader took control of the party in 2015. Recapping the reasons for acrimony between British Jews and Corbyn, Tablet’s Yair Rosenberg compiled an abbreviated list of incidents recently:

Back in 2010, Corbyn spoke at Zomlot’s wedding, where photos captured him celebrating with the bride and groom. In the past, Corbyn has praised, defended, and shared platforms with bigots who claim Jews bake Passover matzo with the blood of gentile children and that the Mossad did 9/11.

Like all arguments over the meaning of words, this one serves as a proxy for bigger issues. Corbyn’s brand of left-wing anti-imperialist politics has involved, not only opposition to Zionism and Israeli state policy, but an embrace of Palestinian and Islamist terrorism directed against Israel and the West.

In Blair’s estimation, while Corbyn is not personally an anti-Semite, “Antisemitism is one aspect of what is a deeper problem with the politics of Jeremy Corbyn and the people around him which is sort of a visceral anti-Western position.”

The former prime minister’s comments echo the analysis offered recently by Anshel Pfeffer writing in Haaretz:

Anti-Western regimes, failed communist and socialist systems, “freedom fighters” and the fight for justice for the Palestinians cannot, in his view, be contaminated. He therefore believes that no-one who fervently believe in these causes – like him – can hold abhorrent beliefs at the same time.

In Corbyn’s simplistic black-and-white world, you can’t be a communist or true socialist and an anti-Semite as well. You can’t truly support justice for the Palestinians and be an anti-Semite, because the former innoculates you from the latter.

Pfeffer’s column was published August 3, several weeks before the release of a recording from 2013 in which Corbyn complained that British Jews whom he called ‘Zionists’ were unable to understand ‘English irony.’