In polls of the greatest British TV drama series, the BBC adaptation of John le Carré’s Tinker Tailor Soldier Spy ranks highly, alongside ITV’s version of Evelyn Waugh’s Brideshead Revisited.

Curiously, though, the first of these landmarks in upmarket screen drama owed its existence to the second.

In the 1970s, the BBC, during one of its periodic crises over justifying the licence fee to politicians and the media, craved a starry, classy, filmed book, and had been negotiating the rights to Waugh’s story of a Catholic aristocratic family. When, unexpectedly, the estate sold the book to Granada Television, Jonathan Powell, running BBC Drama, was asked to quickly find a replacement brainy treat. He settled on the 1974 first volume of Le Carré’s trilogy (later umbrella-titled The Quest for Karla) about the search by George Smiley, a Sherlock Holmes of the spook world, for Russian double-agents in the British secret service.

Healing some BBC wounds by reaching TV in September 1979, two years before ITV’s Brideshead, BBC Two’s Tinker Tailor Soldier Spy, had Alec Guinness’s Smiley taking reaction shots to new levels of attentive reflection in episodes of such deliberative pace that, at this early stage in the era of home video recorders, viewers sometimes wondered if they had accidentally engaged the freeze-frame function.

Guinness’s signature mannerism in the role was taken from the novels – where Smiley was observed to “polish his spectacles with the fat end of his tie” – but, on TV, it served the purpose of animating the long silences necessary to show the spy’s slow laying of interrogational traps into which his quarry might fall.

The pacing was so radical that even as clever a reviewer as Clive James declared the first episode “dull … turgid … incomprehensible”, and, after the third, dismissed the series as “a concerted attempt to inflate a thin book into a fat series”.

In retrospect, as confirmed by recent re-screenings on BBC Four, the show was a harbinger of “box set TV”, decades before the concept existed. Few viewers now would think to complain that a show is too convoluted, involving or leaves space for actors to unravel layered characters: the epic suspect-quizzing scenes in Jed Mercurio’s police corruption series Line of Duty are clearly influenced by the Le Carré series.

The then pioneering experiment continued with a sequel, Smiley’s People (BBC Two, 1982), with Guinness bringing his glasses to an even brighter shine, and A Perfect Spy (BBC Two, 1987), an adaptation of the author’s most autobiographical novel, in which Magnus Pym (Peter Egan) becomes a secret agent after learning the dark arts of deceit from his conman dad, Rick (Ray McAnally).

Revolutionary for TV, these series were also rehabilitative for Le Carré. As Peter Bradshaw notes elsewhere, the writer was in demand from cinema in the early and later stages of his output. However, those three big BBC series saved him from a mid-career period of screen exile.

That gap began when, in the early 70s, the novels became progressively more serpentine and lengthy, panicking the movie industry about their adaptability. Adam Sisman’s 2015 biography of the novelist quotes a letter from the director Karel Reisz (This Sporting Life, The French Lieutenant’s Woman) rebuffing a producer who was interested in filming Tinker Tailor Soldier Spy.

“[His] plots are enormously intricate and complex,” Reisz wrote, “and adapting them always involves one in very painful and unsatisfactory reducing, which I don’t think ever quite works.”

The middle book of the Smiley trio, The Honourable Schoolboy (1977), at three times the length of The Spy Who Came in from the Cold (1963), was even more cinematically challenging. Sisman reports that a producer who asked his staff for a “one page breakdown” of the book, a standard early stage in film-making, was told this was simply impossible.

Television, though, could offer six hours (the standard series length at the time) to depict the long waits and watches that are a feature of spycraft, and the methodical, labyrinthine nature of the interrogation of practised liars and deceivers. Added together, Guinness’s pauses in Tinker Tailor Soldier Spy and Smiley’s People would last the length of an average feature film.

Le Carré was an admirer of Harold Pinter, who had started work on an abandoned version of Tinker Tailor Soldier Spy for ITV, in which Paul Scofield was mooted to play Smiley, and the trademark interrogation scenes share Pinter’s fascination with the significance of silence and the unsaid in so much English speech.

TV had the room to show that happening. The books also proved naturally adaptable in another way. Screen versions often struggle with “voice” writers, whose prose style carries the energy of the novel. But, though Le Carré has a jauntily taut narrative manner – “Two seemingly unconnected events heralded the summons of Mr George Smiley from his dubious retirement,” Smiley’s People starts – the books are voice-led in a more dramatic sense. The centrality of questioning demands sustained dialogue sequences, driven by the sharp ear of a writer who was a gifted mimic, and made thrilling audiobook recordings of most of his canon.

Also perfect for the medium – and the great depth of British acting – is a Dickensian richness of characterisation. As in Jacobean drama, the characters often have defining names – Smiley is, ironically, very glum; spy Oliver Lacon, is, indeed, laconic; Rikki Tarr a growly smoker; and there are two submerged sexual puns under Connie Sachs, a rare woman in the spy ring.

In 2010, two of the author’s sons, Stephen and Simon Cornwell, formed a TV production company, The Ink Factory, beginning a second major phase of Le Carré television. A UK-US co-productions of the novel The Night Manager (BBC One, 2016), with Hugh Laurie as a satanic arms dealer and Tom Hiddleston playing a reluctant spy, became a huge success in the box-set culture that the author had helped to create.

Typically, the writer brought the same meticulous integrity to work for screen as for the page. The BBC and its American partner in The Night Manager, AMC, hoped for multiple further seasons, but the source author pointed out that he had only written one novel about the characters. Instead, the same teams made a six-parter from another novel, The Little Drummer Girl (BBC One, 2018), with Florence Pugh as an actor who infiltrates a Palestinian terror cell.

While posthumous publication of novels is thought unlikely, much more screen-JLC seems assured. A multi-episode version of The Spy Who Came in from The Cold is in production at The Ink Factory. It is also reported that the author, between recent novels, had worked on various scripts, original and adapted.

Of his known works, the one that got away remains The Honourable Schoolboy. The BBC filmed only the first and third books in the Smiley trilogy because, in the 80s, the settings – Hong Kong, Singapore, Thailand, Cambodia, Vietnam – made the middle story logistically and financially impossible. The layered narrative would also have required at least a dozen hours of screen time.

Now, though, the active search of streaming networks for long, complicated content, and the scope for international co-funding and casting, make Le Carré’s most difficult fiction feel ideal for Netflix treatment.

And, if the various film rights can be untangled, there must be scope for an epic multi-season mashup of all 10 books in which Smiley appears, from Call for the Dead (1961) to A Legacy of Spies (2017). Drawing out the central thread of Le Carré’s writing – Britain’s deluded attempt to maintain its imperial significance, from Suez to Brexit – such a series could be one of the greatest achievements of the style of intricate long-form television that the BBC Tinker Tailor Soldier Spy effectively began.

Mark Lawson Talks To … John Le Carré is on BBC iPlayer