Beginning in the 1960s, Ash wrote a series of novels, including "Choice of Arms" and "Ride a Paper Tiger". Politics, however, remained his chief interest. Finding him too quirky and individualistic, the Communist Party rejected his application for membership, and he co-founded the Communist Party of Britain Marxist–Leninist. He also brought his academic background to bear on the subject, publishing a study entitled "Marxist Morality". In later life Ash served for several years as chairman of the Writers' Guild of Great Britain and helped to encourage young writers through his work as a script reader for BBC Radio and later as literary manager at the Soho Theatre. His book "The Way to Write Radio Drama" remained the best on the subject for more than 20 years. Later, he was able to work as a freelancer for the BBC's radio drama department as a script reader.