“Now I'm not a conspiracy theorist, but I'll tell you what - one of the best forms of trying to hide from the atrocities that you are committing is to go on the offensive and to actually create a story that does not exist for people on this platform, the trade union movement or, I have to say, for the leader of the Labour Party.”
A spokesman for the PCS echoed Mr Serwotka’s comments, saying: “We should not allow the issue of antisemitism to be used by people who are attempting to silence Palestinian voices as they legitimately struggle for their rights and a sovereign state.
“Mark spoke at a Palestine Solidarity Campaign fringe event at the TUC – an organisation PCS is affiliated to.
“He made the point at the start of the meeting that we need to oppose antisemitism in society and within the Labour movement.”
Mr Serwotka, who has been PCS general secretary since 2000, is a staunch ally of Jeremy Corbyn, and recently appeared alongside outspoken far-left MP Chris Williamson at a Momentum event in Kent, which was chaired by Jackie Walker, who is currently suspended from Labour over antisemitism allegations.
Marie van der Zyl, the president of the Board of Deputies, called for Mr Serwotka to apologise, accusing him of "demeaning his office by trading in conspiracy theories and stock antisemitic tropes".
She added: "The only reason Labour’s antisemitism crisis remains in the media is Labour’s failure to deal with it. PCS members should consider whether they want to be represented by such a man."