More than 2,000 supporters of Jeremy Corbyn have backed an open letter suggesting a Jewish-organised protest against antisemitism in the Labour Party was the work of a “very powerful special interest group”.

The open letter, posted to Mr Corbyn, claimed the organisers of Monday’s demonstration had used their “immense strength” to “employ the full might of the BBC” in order to launch an “onslaught” against the Labour leader.

The event was organised by Jewish community groups the Board of Deputies and the Jewish Leadership Council.

The letter claims the organisers had sought to use their “history” and ”influence” to “dictate who the rest of us can vote for or how we vote”.

It comes as Mr Corbyn battles to respond to allegations he has failed to adequately address antisemitism among his supporters.

The letter was posted on the “We Support Jeremy Corbyn” Facebook group and was “liked” by more than 2,000 of the group’s followers. Almost 1,000 commented asking for their names to be added to the text.

Coming the day after Monday’s protest, it states: “Yesterday we witnessed the full onslaught of a very powerful special interest group mobilising its apparent, immense strength against you.

“It is clear this group can employ the full might of the BBC to make sure its voice is heard very loudly and clearly. It is a shame not every special interest group can get the same coverage.”

It adds: “But, and it is a very big BUT, we live in a democracy, a one member one vote democracy and no special interest group, regardless of their history or influence, can be allowed to dictate who the rest of us can vote for or how we vote.”

It was posted by a user named Frances Naggs, who said they were a Labour Party member in the Staffordshire Moorlands constituency. The Independent has approached the leader's office for a comment.

The news came as an ally of Mr Corbyn was forced to resign as chair of a key Labour disciplinary panel after a leaked email revealed she had argued that a council candidate who claimed the Holocaust was a “hoax” should not be suspended from the party.