Prominent Labour-supporting Jewish Londoners have written a devastating letter to Ed Miliband expressing their profound concerns about mayoral candidate Ken Livingstone.

The letter, a copy of which has been seen by the JC, was written in response to a meeting held on March 1 at which Mr Livingstone stood by his decision to embrace radical Islamic cleric Yusuf al-Qaradawi and take money from the Iranian state broadcaster Press TV.

Most damaging for Mr Livingstone is the revelation that he believes Jews will not vote Labour because they are rich. The letter states: "Ken, towards the end of the meeting, stated that he did not expect the Jewish community to vote Labour, as votes for the left are inversely proportional to wealth levels, and suggested that as the Jewish community is rich we simply wouldn't vote for him."

The letter explains to Mr Miliband that Jewish Labour supporters were finding it "harder and harder to consider voting for Ken".

At the heart of the critique is the fear that Mr Livingstone's language when discussing the Jewish community, Israel and Zionism, is close to classic antisemitism.

"Ken determines Jews as a religious group, but does not accept Jews as an ethnicity and a people, and did not respond on this, other than to say that as an atheist he found this hard to comprehend. In the same way that Black, Irish, Women and LGBT groups are afforded the right to determine their own identity, many of us feel that Ken doesn't afford Jews that right."

The letter reveals that Mr Livingstone used the words Zionist, Jewish and Israeli interchangeably and did so "in a perjorative manner".

The Jewish Labour figures behind the letter, who include Liberal rabbi Danny Rich and former Limmud chair Andrew Gilbert, express concern to the Labour leadership that Mr Livingstone has aligned himself with the politics of radical Islam.

"The real and more pressing issue is that of the strong perception that Ken is seeking to align himself with the politics of the Muslim Brotherhood and the Iranian regime, whilst ... turning a blind eye to Islamist antisemitism , misogynism and homophobia."

The authors of the letter added: "We are concerned that this is more about infantile, far-left politics, being seen to take a stance against whatever the anti-establishment or anti-imperialism cause of the moment is."

The letter was written ahead of a meeting between the Jewish communal leadership and Ed Miliband later this month, when the issue of Mr Livingstone will be top of the agenda.

The latest cracks in the already strained relationship between Mr Livingstone and the Jewish community came in a week in which the Labour mayoral candidate pledged to make London a beacon for the words of the Muslim prophet Mohammed.

He was speaking at the controversial North London Central Mosque at Finsbury Park, which is run by the Islamist Muslim Association of Britain. Mohammed's last sermon is often seen as a plea for racial equality, as it states that "a white has no superiority over a black nor a black has any superiority over white, except by piety and good action".