A pensioners’ campaign group has dismissed Labour’s antisemitism crisis as a “toxic conspiracy” and has compared those who have protested about the issue to “Salem witch-hunters”.

In a letter sent to Labour leader Jeremy Corbyn, Baroness Shami Chakrabarti and to every Labour MP, the Merseyside Pensioners Association (MPA) condemned what it described as “the current antisemitic hysteria”.

The group is based in the same Liverpool building as the Unite union’s regional headquarters.

The MPA said the current row over Jew-hate had been sparked by “a toxic mix of Tories, Blairites and right-wing self-styled representatives of the 'Jewish community'. "

Attacking those it suggests are trying to bring Mr Corbyn down, the MPA letter adds: "McCarthy and the Salem witch-hunters were eventually exposed as charlatans.

“We call on the leadership to stand firm and the current onslaught will suffer the same fate.”

The letter suggests Labour activists are wrongly being disciplined for claiming “criticism of the policies of Netanyahu’s Israeli State is antisemitic”.

The MPA campaigns to improve the well-being of hundreds of elderly people living in the city.

One post on the group’s Facebook page includes a photograph of a Palestinian flag being waved behind a “Save the NHS” banner.

Other leading supporters of the group include former Militant tendency supporters Derek Hatton and Tony Mulhearn – who were both expelled by Labour in the 1980s.

Mr Mulhearn has launched a string of attacks against Jewish Labour supporters on his Twitter feed and his blog.

In one social media message he wrote earlier this month: “Shock, horror: Jewish donor quite [sic] Labour!"

On his Socialist Perspective blog he echoes the MPA letter by writing: “Wild accusations, alternative facts, special prosecutors — the Salem witch trials of 1692 had it all. Sound familiar?

"Witch-hunts from Salem to McCarthy are rooted in preserving the material interests of powerful people who ruthlessly exploit fear and prejudice to undermine those who threaten their privileged position.

"The current antisemitic hysteria, generated by a toxic mix of Tories, Blairites fearing re-selection, right wing self-styled representatives of the ‘Jewish community’, cheered on and encouraged by a feral media, meets all the classical traits of the witch-hunt."

Two Jewish Liverpool MPs, Louise Ellman and Luciana Berger, have been at the forefront of the fight against antisemitism in Labour.