[3] Anthony Farrant is a naive 1930s businessman who pays a visit to Germany on the way home from a business trip, and falls under the politically dubious spell of charismatic financier Erich Krogh.

[6][7] Critic Philip Strick suggests that Greene, fully aware of the liberties moviemakers could take with source novels, was reluctant in this case because of the book's personal nature.

[10] The screenplay to be used, by Wolf Mankowitz, retained the Swedish setting but moved the action to the present day: Duffell recalled "lots of pot smoking and copulation.

[10] The script ultimately used, by Duffell and Desmond Cory, stayed in the 1930s but moved the plot from Sweden to Germany; it also removed the detail that Tony and Kate are twins.

[6][18][19] York as Tony makes his first appearance, disembarking from a steamship, in Rijeka harbour;[16] the scene where he and Kate reunite at a French seaside resort was filmed in Opatija;[19][20] the lakeside villa where Krogh throws a party for Nazi dignitaries was actually on the shores of Lake Bled and had been used as a residence by Josip Broz Tito.

[25] Song Remembering (written-by John Scott and Arthur Hamilton, arranged by Larry Wilcox) sung by Lana Cantrell, was released on vinyl, LP (US) by East Coast Records.

[28][c] David Robinson, in The Times, was unsure that relocating the action to 1930s Berlin was wise – "the familiar symbols (not even excluding the obligatory cabaret and decadent party scene) remove any of the ambivalence of the novel's original atmosphere" – but singled out for praise the production values and the acting, especially Hordern's supporting performance as Minty, "flapping around in a greasy mac, and peering through a fog of smoke as he indecently mouths his worn-out fag-ends".

Gibbs also felt that it altered the story in interesting ways: Krogh is "made considerably more sympathetic by his frauds now being worked not on investors, but on the Nazi government".

[19] In another positive review, for The Sunday Times, Derek Prouse likewise thought the transposing of the action "valid": "the locations and set dressing are a potent asset in the creation of an atmosphere of quiet menace".

Nonetheless he praised York's performance as the protagonist, even though the actor's casting evoked memories of the recent Cabaret, and concluded: "This is a worthwhile film, broadly faithful in spirit to Greene's intentions and well acted down to the smallest supporting part.

[32]Nonetheless, he later told The Guardian that it was one of the few screen adaptations of his books that he approved of, and had wanted Duffell, whom he called "a friend of mine", to write and direct The Honorary Consul.