Leaders from the Jewish community have launched an attack on Jeremy Corbyn, claiming he has sided with anti-Semites "again and again".
An open letter from the Board of Deputies of British Jews and the Jewish Leadership Council to the Labour leader was published as Corbyn said he was "sincerely sorry" for the pain caused by "pockets" of anti-Semitism within the Labour party.
However, the letter - aimed personally at Corbyn - claims he is "repeatedly found alongside people with blatantly anti-Semitic views" but "claims never to hear or read them".
A protest has been planned by the organisations to take place outside Parliament ahead of delivering the letter to Labour MPs and peers.
It will be presented at a meeting in which anti-Semitism concerns will be discussed. Corbyn, however, is not expected to attend.
The letter reads: "Today, leaders of British Jewry tell Jeremy Corbyn that enough is enough."
There was a "repeated institutional failure" to properly address Jewish concerns and to tackle anti-Semitism.
"We conclude that he cannot seriously contemplate anti-Semitism, because he is so ideologically fixed within a far-left worldview that is instinctively hostile to mainstream Jewish communities."
The latest row was triggered after reports of Corbyn posting a comment on Facebook in 2012 where he appears to offer a show of support for the painter of a mural at the centre of an anti-Semitism row whose controversial street art was about to be painted over.
Corbyn later said he sincerely regretted not looking properly at the "deeply disturbing and anti-Semitic" picture before telling artist Mear One he was in "good company" among artists who had had work removed.
The Labour leader has now said he will meet representatives from the Jewish community over the coming days.
Corbyn said: "Labour is an anti-racist party and I utterly condemn anti-Semitism, which is why, as leader of the Labour Party, I want to be clear that I will not tolerate any form of anti-Semitism that exists in and around our movement. We must stamp this out from our party and movement."