Oswald Mosley’s attempt to build up support overseas in the years after the Second World War was thwarted by his commitment to antisemitism, according to a newly released Foreign Office file.

The British fascist leader planned to recruit support in America and publish a newspaper advancing his extremist views.

According to one memo: “Mosley considers that Germany is the key to the struggle between East and West and that he is the only living man capable of swinging her away from Russian influence.”

The files detailed his negotiations with a Wall Street broker who was prepared to offer him one million dollars “on the condition that the campaign be directed solely against communism and that antisemitism should be dropped. Mosley is reported to have refused to accept the proviso.”

It also reveals that Whitehall feared Mosley’s presence in the US could be a disaster. In a memo of January 1948, diplomat Aubrey Halford noted that any political success he achieved would be “embarrassing beyond calculation”.