UK- Deep Throat, probably the most controversial film of all time, was given its first UK cinema screening this weekend – 33 years after its debut in America. The Everyman Cinema in north London turned itself into a special club for the occasion to allow it to be shown as an R18, the British Board of Film Classification’s highest restriction.

Daniel Broch, managing director of Everyman Media, described the screening as “more of an event than a hard-porn show”. However, he made his excuses early and left to be with his family.

The film is famous – and infamous – in myriad ways. Apart from the title (which, strangely, inspired the naming of the Watergate mole), there is the storyline (a sexually unfulfilled woman mislays her clitoris until a doctor discovers it buried in her oesophagus), and the fact that it became the most profitable film ever. It was made for $25,000 (£13,700) and has grossed more than $600m.

Federal agents tried to prosecute it out of existence. Its male star, Harry Reems, was convicted, alongside the mafia who had distributed it, for “conspiracy to transport obscene materials interstate”. Perhaps, the film is most famous for starring Linda Lovelace “as herself” and her facility for fellatio.

Deep Throat and its stars were championed by an unlikely alliance of groups. Pro-pornography campaigners claimed it heralded a brave new world of sexual liberation. And for one short year it did – the most fashionable people in New York lined up outside cinemas showing the film to proclaim their sophisticated permissiveness.

When the FBI tried to close it down, Hollywood A-listers such as Warren Beatty, Shirley MacLaine and Jack Nicholson rallied to the film’s support by very publicly seeing it again. And again. They went on to host benefits for Reems’ legal defence fund.

When Lovelace, formerly Linda Boreman and later Linda Marchiano, alleged in 1980 that she had been forced to make the movie at gunpoint, by her husband/manager Chuck Traynor, she was in turn championed by anti-pornography feminists, led by Andrea Dworkin and Gloria Steinem, who held her up as a classic victim.

Lovelace became a born-again anti-porn campaigner, saying: “When you see the movie Deep Throat, you are watching me being raped. It is a crime that movie is still showing; there was a gun to my head the entire time.” She acknowledged that she was talking of Traynor’s role in the film, not that of her co-stars.

Shortly before she died, after a car crash in 2002, she became more reconciled to her past – she did a soft-focus lingerie shot for the magazine Leg Show, and attended signings where she autographed Deep Throat nick-nacks.

Lovelace was paid $1,250 for the film, Reems $250. Most of the $600m profit rests with the mafia. As for Reems, he became a despairing drunkard until he found God and property. He is now a real estate broker in Park City, Utah.

The film was finally banned in the US in 1973. It was never shown in Britain, where hard pornography was banned in cinemas, though plenty of people saw it on pirate videos at home. The R18 certificate, introduced in 1999 by the BBFC, allowed Deep Throat to be screened at a cinema, but it never was.

Only now, with the documentary Inside Deep Throat newly released (and showing in a double bill at the Everyman) has there been any call to give the original a cinema release. The only print available, imported from America, will travel around the country for special screenings.

In the documentary, author Erica Jong dismisses the film’s leitmotif, the throat clitoris, as a ridiculous male fantasy. The feminist writer Julie Bindel said: “Deep Throat is bloody horrible. I would shoot the director of that film, but also put in irons the distributor and cinema owners and all those reviewers who think it is funny showing a woman being raped on screen like some postmodern joke. It’s not a joke.”

The film itself is a strange mixture of gritty realism, Carry-On style comedy, kitsch musical and hard core pornography. Deep Throat’s director, former hairdresser and swinger Gerard Damiano, obviously fancied himself as an auteur.

The opening sequence, in which Lovelace drives through a suburban landscape on a glistening summer’s day, music blasting out joyously, could be early Scorsese. She reaches home, drops her two bags of shopping and casually addresses her friend. It soon emerges that her friend is receiving cunnilingus while chatting and smoking. She suddenly remembers her manners, looks down towards her provider and asks him: “D’you mind if I smoke while you eat?”

At times, Damiano reveals a talent for comic dialogue, such as when Dr Young makes his discovery.

Dr Young: “Oh, it’s amazing, truly amazing, Miss Lovelace. You don’t have one.”

LL: “Doctor, I’m a woman I’m not supposed to have one.”

Dr Young: “No, I don’t mean one of those … there’s no clitoris here.”

LL: “Well I’ll be damned …”

Dr Young: “No wonder you hear no bells; you have no tinkler.”

At times, Deep Throat borders on the surreal. Hard-core sex is played out to a happy-clappy musical backdrop of I’d Like to Teach the World To Screw – adapted from the song used to promote Coca-Cola. But for the most part, the film is dull. The sex is boring. While Lovelace spends much of the film involved in oral gratification, it’s not unlike watching a skilled sword swallower at work. And once you’ve seen one sword swallowed, you’ve seen them all.