Ms Manson was one of five speakers at the event, entitled ‘Resisting the Rise of the Racists and Fascists’, which included debate on antisemitism.
Another speaker was Weyman Bennett, a member of SWP’s central committee and co-convenor of SUTR.
Three years ago, Mr Bennett was at the centre of claims he was involved in the cover-up of a sexual assault of young SWP member.
At the time, the UK’s most prominent far-left organisation attracted widespread criticism of the way it handled rape accusations against a senior party figure.
SUTR was set up shortly afterwards.
A spokesperson for JWA said: “We are aware that our communications manager used to be vice-chair of an anti-racist organisation. She is no longer associated with this organisation.
“We take all allegations of sexual assault extremely seriously and work tirelessly to support Jewish women survivors of domestic and sexual violence on a daily basis.”
Rabbi Wax said: “I resigned from Stand Up To Racism to avoid any potential perceived conflict of interest with JWA with whom I have worked tirelessly for the last seven years, supporting Jewish women affected by domestic and sexual violence.
“Also, as a rabbi of 25 years standing I have been committed to fighting antisemitism and racism wherever it stems from. I will continue to devote myself to these causes.”
