Making waves: How do we view sex on TV?

It's the shot of the tube of lubricating gel that may well prove the final straw for some newspapers. The offending item appears at a climactic moment of what the screenwriter Andrew Davies is already calling "the bushes scene", a feverish sexual encounter near the beginning of BBC2's three-part dramatisation of Alan Hollinghurst's Man Booker Prize-winning novel, The Line of Beauty.

The drama's protagonist, a young gay man named Nick Guest (played by Dan Stevens), gets up close and personal with Leo Charles (Don Gilet), a man he has just met through a lonely-hearts column. After a drink in the pub, they repair to the bushes in the communal gardens of the Notting Hill home where Nick is staying.

The day I visit the set of The Line of Beauty, however, the film-makers do not seem unduly concerned about newspapers getting all hot and bothered over their work. "I'm not worried about the Daily Mail," says Saul Dibb, the director. "They always foam at the mouth - that's their job!"

Kate Lewis, the producer, is equally unperturbed. "I'm sure there will be members of the BBC2 audience who say that scenes of gay sex are not for them. Also, I'm afraid, there are still a lot of homophobic people out there. " Davies agrees, saying simpy: "For some tastes, it'll be too out there."

But it could have been even farther out there. In his screen version, Davies has tempered the more graphic sequences of the novel, leading to accusations in some quarters that he has watered it down. This is not a charge which is usually levelled at Davies, also responsible for such publicity-fuelling, "sexed-up" adaptations as Tipping the Velvet, Moll Flanders and The Chatterley Affair.

"Writing sex scenes for television is an enormously tricky business," Davies says. "You have to get the balance right. Less is more, but you don't want to get so timid that there's nothing there. It's all about small, telling details. Whether you're writing about homosexual or heterosexual sex, I'm interested in showing the emotional impact on the characters and want the audience to identify with them.

"That means a high proportion of close-ups on eyes and mouths and as little as possible shot from six feet away - which tends to turn the audience into voyeurs. Then they feel guilty and uncomfortable about prying into someone else's sex life.

"The director, Saul Dibb, and I agreed that we should shoot quite a lot of footage of love-making and then see what we thought about it in the edit. But that soon turned into headlines - 'Davies tones down Hollinghurst' - which got a lot of aggrieved press from gay men. They were saying, 'he didn't tone it down for Tipping the Velvet - what's wrong with us?'.

"Contrary to popular belief, we're not setting out to provide a pornographic service! But gay viewers won't be disappointed - they can rest assured, there are as least as many lively goings-on as in Tipping the Velvet."

These scenes are undoubtedly what will grab the headlines, but it would be a mistake to get too hung up on sex - this is not a drama with just one thing on its mind. Within its epic sweep, The Line of Beauty encompasses everything from the lasting impact of Mrs Thatcher's reign and the pernicious influence of the British class system to the devastating effect of the Aids epidemic and the excesses of the tabloids. It's Everything You Always Wanted to Know About the 1980s, (But Were Afraid To Ask).

I'm sitting with Davies in the manicured grounds of a gorgeous Georgian house in High Barnet. With its colonnaded exterior and sumptuous interior - all ornate carriage clocks and marble statues - this is the location for many scenes in the drama.

Calling The Line of Beauty "a masterpiece", Davies says that he had already inquired about adapting it by the time he was three-quarters of the way through reading it. As Peter Conradi commented in his review for The Independent on Sunday, the novel is "a brilliant recreation of that bigoted, nepotistic, racist, callous and mean-spirited epoch... fabulous".

Book-ended by Margaret Thatcher's two landslide general election victories of 1983 and 1987, and overshadowed by the growing danger of Aids, the drama recounts events through the prism of a young outsider, the appropriately named Guest. He comes down from Oxford to live in the magnificent Notting Hill family home of Toby Fedden (Oliver Coleman), an old university chum for whom Nick harbours a secret crush. Working for a PhD on Henry James, he is fixated by the idea of beauty and is sucked into the superficially grand, High Tory universe of the Feddens.

As Nick becomes increasingly close to the family - Toby's father, rising Tory MP Gerald (Tim McInnerny), wealthy mother Rachel (Alice Krige), and emotionally unstable sister, Catherine (Hayley Atwell) - he is perfectly placed to observe the decade unfolding from the heart of the Establishment. All that, however, merely acts as the backdrop to the very personal story of Nick's sentimental education. As he falls in love first with the black council worker Leo and then a louche millionaire, Wani (Alex Wyndham), Nick unlocks his long-closed sexuality.

The key to hooking viewers is to make them empathise with Guest. "It's so important that the audience identify with Nick," says Davies. " I hope a mainstream audience will go through this with him - as they did with the characters in Tipping the Velvet. If you win the audience's sympathy, they'll go on the journey with you.

"Nick thinks that knowing things like the provenance of antique furniture is fundamentally important; but eventually he sees that it's not. What's important is to find someone to love - the thing we all want."

'The Line of Beauty' starts at 9pm on 17 May on BBC2