The Imperial Fascist League went into a steep decline upon the outbreak of World War II, after Leese declared his allegiance to "King and country", to the displeasure of pro-German members.

[6] The IFL soon shifted away from Italian fascism (it originally used the fasces as its emblem) after Leese had met the Nazi Party propagandist Julius Streicher in Germany.

Soon, anti-Semitism became the central theme of IFL policy and its new programme, the 'Racial Fascist Corporate State', stressed the supremacy of the 'Aryan race'.

As a result of that conversion, the IFL enjoyed a higher profile than its membership might suggest, in large part due to the funding that it received from Nazi Germany paid through the English correspondent for the Völkischer Beobachter, Dr. Hans Wilhelm Thost.

[3] Indeed, by the mid-1930s the IFL had turned against the Italian model so much that it denounced Benito Mussolini as a "pro-Semite" and claimed that the Second Italo-Ethiopian War had been organised by Jews.

[8] In 1932, Robert Forgan approached the IFL and suggested that it should merge into Oswald Mosley's British Union of Fascists, but the offer was declined.

The campaign culminated in an incident in Great Portland Street in which 50 Blackshirts disguised as communists invaded the stage to attack Leese before they caused considerable damage to the hall in an attempt to force a large repair bill onto the IFL.