John McDonnell is facing accusations of hypocrisy as it emerged that he is president of a group that is campaigning in support of Labour figures accused of anti-Semitism and verbal abuse of an MP.

The shadow chancellor is president of the Labour Representation Committee (LRC), which has posted a statement on its website declaring that Ken Livingstone, the former London Mayor, was the victim of a "witch hunt" and that the controversial comments over which he resigned, were "not remotely antisemitic."

In May Mr McDonnell pledged to "call out" hard-left websites propagating anti-Semitism. The Telegraph's disclosures prompted calls by Labour MPs for him to resign from the group.

In response, his spokesman said Mr McDonnell was "just an honorary president of the LRC, and plays no role in the content or decision making process of the organisation."

In recent weeks the group also defended Stan Keable, a Labour member who was dismissed from his role as a council worker in west London after claiming that Zionists had "collaborated" with the Nazis.

It has separately created a page on its site advertising a national speaking tour by Marc Wadsworth, the Labour activist expelled from the party in April for verbally attacking an MP.