(JTA) — Sixty-eight British rabbis signed an open letter decrying anti-Semitism in the country’s Labour Party and calling on the party to accept the International Holocaust Remembrance Alliance definition of anti-Semitism.

In a rare united position, rabbis ranging from ultra-progressive to haredi Orthodox signed on to the letter.

Labour’s national executive committee is set to meet Tuesday to approve the party’s new code of conduct, which will include a softened version of the alliance’s definition of anti-Semitism. Labour’s definition omits at least four points featured in the original one, including accusing Jews of “being more loyal to Israel” than their own country; claiming that Israel’s existence is a “racist endeavor”; applying a “double standard” on Israel; and comparing “contemporary Israeli policy” to that of the Nazis.

“The Labour party’s leadership has chosen to ignore those who understand anti-Semitism the best, the Jewish community,” the rabbis said in their letter, which was published in The Guardian. “By claiming to know what’s good for our community, the Labour party’s leadership have chosen to act in the most insulting and arrogant way.”

The Guardian reported that legal advice given to the Labour Party by the Jewish Labour Movement ahead of Tuesday’s meeting warns that the new definition of anti-Semitism could violate the Equality Act in Britain.

The advice, according to the Guardian, says that in crafting the new definition, Labour has ignored the so-called Macpherson principle – that a racist incident is one perceived to be racist by the victim – and therefore when it comes to anti-Semitism, Jews are being treated less favorably than other groups.

A Labour spokesman told the newspaper that is “entirely untrue” that the party’s code of conduct is not fully in line with the Macpherson principles.

The Equality Act passed in 2010 is an anti-discrimination law that demands equal treatment by employers and service providers regardless of age, disability, gender, marital status, race, religion or belief, or sexual orientation.

Labour under Jeremy Corbyn, a hard-left politician who has called Hezbollah and Hamas his “friends” and who is fighting accusations of harboring anti-Semitic sentiments, has come under intense scrutiny in the media over anti-Semitic rhetoric by its members. In 2016, an interparliamentary committee accused Labour of creating a “safe space for those with vile attitudes towards Jewish people.”

Corbyn has maintained that Labour will not tolerate racist rhetoric by its members. Dozens were kicked out over anti-Semitic statements. However, the party has kept on many Labour members whom Jewish community leaders said engaged in anti-Semitic hate speech. In recent months, Corbyn for the first time has encountered protests over his party’s anti-Semitism problem during work visits abroad.