They are the titans of the spy novel, who have elevated thrillers to the level of literary fiction. Much imitated, much adapted by the big and small screens, Ian Fleming and John Le Carré have painted our picture of post-war espionage: Fleming through the dashing figure of James Bond, with his lush locations and Martinis as icy as his heart; Le Carré through his damning portrait of the British secret service drawn from his own time in MI5 and MI6. But which of the two novelists is the greater?

In this thrilling contest, Fleming’s case was made by Anthony Horowitz, creator of the bestselling Alex Rider spy novels and author of the official Bond continuation novel Trigger Mortis. Championing Le Carré – whose memoir about his life as a former spy currently sits in the bestseller lists – was David Farr, Emmy-nominated screenwriter of the BBC’s adaptation of The Night Manager.

‘Fleming is one of the very few writers – Charles Dickens and JK Rowling might be two others – who have transcended fiction, who have created stories that capture a particular time and place, that are universally recognisable and that are, it would seem, immortal,’ says Horowitz. ‘George Smiley is a fascinating character. James Bond is an icon. That’s the difference.’

By contrast, pointing to Le Carré’s own experiences in the secret service, Farr says: ‘John Le Carré turns espionage into existentialism. His canvas is betrayal — of the realm and of the heart. His greatness comes from the personal nature of that exploration.’

To illustrate their arguments, Horowitz and Farr called on a cast of actors to bring the novels to life.