A Labour Party member who was readmitted by its national executive committee runs a website which carries a number of antisemitic articles.
Gerry Downing runs the Socialist Fight group, which has defended Daesh and posted an article which stated: "Why Marxists must address the Jewish Question".
Mr Downing had previously been excluded from the party last year but was later reinstated as a full member.
His site carries articles which compare Zionism to Communism and questions aspects of the Holocaust, including Nazi culpability.