With his cockney accent, bureaucracy, supermarket shopping, home cooking and functional Ford Zodiac, it is easy to see Harry Palmer as an anti-Bond—and he was certainly positioned as such—but The Ipcress File also owes a debt to the private detective narratives of film noir. His investigation, all old-fashioned legwork and form filling in London’s less glamorous postcodes rather than jet-setting between exotic locales with the latest spytech, is engrossing and manages to be mysterious and pleasingly twisty without being convoluted, and it proceeds at a decent clip.

Released the year after Zulu and the year before Alfie, The Ipcress File sees Michael Caine on the cusp of stardom. He is excellent as Palmer, being effortlessly sexy and cool as the working-class Everyman. The underlying conspiracy is a bit silly, truth be told, but Caine is mesmerising and kept me hooked from the get-go.

This is a captivating 1960s spy thriller with a wonderful lead performance. Highly recommended, particularly for those interested in the early responses to James Bond.