A letter sent to the Mayor of London Sadiq Khan protesting about his decision to attend the Board of Deputies annual dinner has sparked anger after its author was openly challenged over his claim to speak on behalf of the capital’s 45,000 Charedi Jews.

Shraga Stern wrote to the London Mayor urging him to turn down his invitation to speak at the 2018 President’s Dinner on Monday November 5, claiming the Board did not represent the Charedi community and that “disenfranchising our community is their stance on education”.

The letter also suggested that if Mr Khan attended the dinner, the Charedi community would switch from backing Labour candidates in Hackney and would no longer be able to vote for him as mayor.

But the JC can reveal that Mr Stern’s letter – which ended with the wording “On behalf of the Charedi community”, and was circulated on WhatsApp - has already infuriated many within his own community.

One message sent back to him from “Stamford Hill Charedi Jew David Spitzer” said: “What a cheek. Your gripe with the BoD appears to be that they have no legitimacy as spokespeople for the Jewish community in Britain.

“By the same token, who appointed you spokesman for the Charedi community?”

Another member of the community told the JC: “Shraga Stern is a dreadful self-publicist. He speaks for no-one but himself. It is a sham that he claims to be able to manoeuvre to vote for a political party on his word alone.”

The letter was picked up by the pro-Jeremy Corbyn website Skwawkbox as proof of disunity within the Jewish community. It was also claimed the letter put Mr Khan in a difficult position.

But in a clear attack on the democratic process, Mr Stern’s letter suggested: “As you will probably know, there are 67,000 Charedi Jews in Britain, with 45,000 of these living in London.

“We urge you not to attend the dinner, as this would be showing your support for what is, essentially, a group of fringe noise makers. We would also like to point out that you have never attended a Charedi event and will most certainly lose our support if you do choose to attend the BoD Dinner.

“In the Cazenove ward of Hackney, we recently supported three labour candidates to election, taking three seats that had been in Liberal Democrat hands for 24 years. This is just one example of how our community supports politicians who work for our good. If you attend the BoD dinner, we would be unable to offer our support in your position as mayor.”

In a statement the Mayor of London’s office confirmed: “Sadiq was honoured to be asked to speak at the Board of Deputies dinner and is looking forward to attending.

“Our religious communities make a huge contribution to all aspects of life in our city and the mayor is always keen to listen the many and varied views within different communities, address their concerns and support their hopes for the future.”