After Eckersley met Sir Oswald Mosley he became involved in his New Party, chairing its London Central Committee. From November 1939 the transmitter he had arranged to put in place at Osterloog was used for William Joyce's broadcasts to Britain and Europe. Eckersley has been described as "at best a foolish Fascist fellow traveller and at worst a traitor". Dolly joined Mosley's British Union of Fascists, outdoing Mosley in her enthusiasm for Nazism, and also the National Socialist League founded by William Joyce after he was expelled by Mosley for being too anti-semitic.