It is only November but I can already predict what will win the best drama category at the next Baftas. I can also say what shouldn’t. The answer in both cases is a trilogy of BBC films by the lauded playwright and director Stephen Poliakoff, who this year celebrates 30 years making television films. Since 1977 Poliakoff has assumed a unique status in British television, an auteur on a rolling commission from the BBC to make exactly the films that he wants on budgets to make other film-makers weep. Not since the very end of Dennis Potter’s career, when the writer of The Singing Detective won permission to direct his own screenplays, has a single creative presence held television executives in such thrall.

Joe’s Palace, A Real Summer and Capturing Maryare three linked films that centre on a large Georgian house in London. Palace and Mary both feature at their heart a naive, possibly subnormal teenage care-taker called Joe, whose main job, in the drama, is to listen to his elders and betters. Each play weighs in at about an hour and 40 minutes. A Real Summer, commissioned by BBC Two’s Culture Show (which is doing a big number on Poliakoff), is a 45-minute bridging piece, a monologue for the actress Ruth Wilson who, as Mary, stars again in Capturing Mary. They are sumptuous pieces, beautifully shot to feature-film standards. In nearly four-and-a-half hours, I noticed only one infelicity by the director of photography, Danny Cohen. Adrian Johnston’s music, alternately mysterious and swooping, is plushly Hollywood.

If television is our true national theatre, then we also get to see our national treasures in these pieces. In Joe’s Palace, Michael Gambon is at his most droll, wistful and enigmatic as the house’s reclusive owner. In Capturing Mary, Maggie Smith plays an older version of the Mary that we meet in A Real Summer. She is prickly, sprightly, sad, attractively alcoholic: very Maggie Smith. In Summer, Ruth Wilson, who was recently Jane Eyre for the BBC, delivers an impeccable younger Mary, a fake debutante who will find the 1960s and Mary Quant dresses more her thing. But Poliakoff’s casting reaches perfection in Danny Lee Wynter, a recent Lamda graduate whose wide eyes and lips pronounce, as somebody’s must in a Poliakoff, permanent awe.

There are two problems with works that so self-consciously boast their own quality and budget. The first is that they must reduce both in quantity and quality the opportunities for other, perhaps younger, film-makers (Poliakoff is 55 next month). Secondly, they make it hard to see the work for what it is. Bernard Levin once said of Stockhausen’s music that it was better than it sounds. Poliakoff’s films are sometimes not as good as they look. His imagination is vivid but it is narrow, and since Shooting the Past in 1999 his work has become mannered and repetitive – one would say clichéd were not his clichés sui generis.

He has become obsessive, in the first place, about the past. This was not always the case. His first television film, Stronger than the Sun in 1977, was a thriller about nuclear power. Bloody Kids for ITV in 1980, directed by Stephen Frears, featured young hooligans running amok. Close My Eyes, his most successful feature film, released in 1991, had a brother and sister so brutalised by Thatcherism, ozone layer depletion and the Aids epidemic that they took refuge in an incestuous affair.

But all the while, tugging at him, was the success of his second TV feature, Caught on a Train (1980), in which the proto-yuppie Peter, played by Michael Kitchen, was almost derailed on a journey across Europe by his travelling companion, the old lady Frau Messner (Peggy Ashcroft). Messner represented old Europe: its secrets, its tragedies, its grandeur. By 1999 and Shooting the Past, preserving European history became the prime moral virtue in Poliakoff’s work.

In this series a wicked American bought and wished to close a picture library; old English eccentricity was portrayed by the librarian Timothy Spall, English grace by his boss Lindsay Duncan. The serial’s antiquarian subject was reflected by its form, which hailed from a gentler age of television drama where long scenes, heavy on dialogue, were the norm. In this drama, the action literally stopped as we gazed at still photographs and listened to tales associated with them. Poliakoff’s Max Bygraves era (“Lemme tell you a story”) had begun.

For a while, we were intrigued, not realising that this was an era. But when Perfect Strangers pitched up two years later using again not only Spall and Duncan but also old pics hoarded by an archivist, the déjà vu was chilling. Once again the action froze to accommodate Jackanories, this time told by, yes, Gambon.

Another two years passed and Poliakoff played a blinder. The Lost Prince in 2003 was about the past – George V – but it was not this time refracted through the present but immersed in it. In the casting of the diminutive Tom Hollander as the king, Poliakoff had discovered – and then worked through – a splendid comic metaphor for the littleness of England at the end of empire.

Then, last year, we were in trouble again as Poliakoff delivered two stately, vaguely linked dramas, Friends and Crocodiles and Gideon’s Daughter. Gideon at least dealt with the present day, but Poliakoff was back trapped in the past in F&C. This time L.P. Hartley’s foreign country was the 1980s, a land of which, naturally, Poliakoff still disapproved. There were no stultifying archives this time but instead sumptuous set-piece, allnight parties filmed in the grounds of Castle Ashby in Northamptonshire – and supposedly heart-stopping visual metaphors: giant butterflies flying into the sky and, ludicrously, a pet crocodile. Poliakoff is a “left-wing” writer, but he is in love with opulence even as he pretends to distrust it.

The new works find him at his most snobbish. Gambon’s abandoned house is cleaned and polished every day by its staff. Joe, standing in for us, walks round it in a state of near orgasm. Visitors, including Mary, tell us repeatedly that it is “beautiful”. At one point its owner, Elliot Graham (Gambon), even sends Joe scuttling off to The Antiques Road Show to get a couple of its snuff boxes valued. Upstairs, a government minister (Rupert Penry-Jones) and his mistress (Kelly Reilly) have five-star sex filmed, as was the congress in F&C, as if Merchant-Ivory had been entrusted with a Playboy video. (In a brief, brilliant scene that reminds us we must never write Poliakoff off, we see Reilly away from the house, bedraggled and bringing up her screaming children.)

Joe’s Palace throws in a castle, given to Elliot as an eighth birthday present, for good measure. In place of black-and-white photos come black-and-white archive film of the 1950s. The monologues are also back, with Gambon and Smith as the ancient mariners. Wilson plays their first mate in her one-off play, reciting the sad tale of Geraldine, last of the dim debs.

Gambon gets to tell the nastiest tale of all in Joe’s Palace. It involves Nazis, Jews and a park, because parks, as in Gideon’s Daughter, represent a high point of civilisation for Poliakoff not to be sullied. In Capturing Mary it is Kensington Gardens’ turn. The plays are full of ghostly memories. In Diana’s backyard, however, a ghost actually materialises.

Despite the film’s various trips into the big house’s cellar and into its mad attics, it was only at this moment that I realised how fully Poliakoff had fled into the Gothic and decided that he had deliberately written and filmed a self-parody. The teller of secret tales in Capturing Mary is a would-be sinister bod in a dinner jacket named Greville. The clue he is not to be taken seriously is that he is played by David Walliams from Little Britain. The secrets that he imparts are pretty grotty: an archbishop who thrashed little boys (Graham Fisher); the “public figure” who kept a girl enslaved (go on, tell us it was Longford). There is nothing Holo-caust-terrible, and this time the mariner’s wedding guest, Mary, is not enchanted but disgusted. Someone tells Greville that he is talking rubbish, and no one disagrees.

The scene near the end has Greville, suddenly out of fashion in the swing-a-ding 1960s, mouthing though his car’s back window: “Help me!” It is the image of a writhing creature trapped in a tank. But Mary does not help him. She turns her back. Perhaps in these shots, one sees Poliakoff, the Westminster schoolboy brought up in a big house in Holland Park, whose grandparents fled Stalin’s Russia in 1924, himself crying for release. Mary finally escapes the confinement by the past and its portentous anecdotes. Is it too much to hope that with this self-satire, Poliakoff has freed himself from it, too?

Joe’s Palace, Sun, BBC One, 9pm; Stephen Poliakoff: A Culture Show Special & A Real Summer, BBC Two, Nov 10; Capturing Mary, BBC Two, Nov 12

Editor's choice

• U2 at Nou Camp Stadium, Barcelona
• The 50 Best Movie Villains
• The 15 golden rules of theatre etiquette