You may have to spend time on some grim and Gothic Web sites to find this out, but he is in fact not a "denier," but a revisionist, and much-hated by the full-dress "denial" faction.It is true that one can find material in Irving's book which "deny the deniers," e.g. his claim that in November 1941 Hitler ordered Himmler to stop the liquidation of the Jews. It seems to have escaped Irving that you can only stop something which is underway.
The pages on Goebbels, as in his books on Dresden, Churchill and Hitler, contain some highly important and damning findings from his work in the archives of the Third Reich. (The Goebbels book contains final proof that the Nazis financed Sir Oswald Mosley's blackshirts in England: a claim that Mosley's many sympathizers have long denied.)
There are many such points. However, given all Irving has said about the Holocaust [and his so-called retraction in the court] there is no doubt that he is a denier.