Julian Fellowes tells a nice story about the night he won the Best Original Screenplay Oscar for Gosford Park. Having been presented with the trophy by Gwyneth Paltrow, she then accompanied him to the room where the press were waiting."God, this is insane," Fellowes commented as they walked into a barrage of flashlights. Paltrow turned to him and said: "Welcome to my life." You suspect Paltrow would find Fellowes's life equally alien, although she may have had a taste of it when she was filming Emma in Dorset. Much of the film was shot in the mansion Fellowes subsequently bought with the fruits of his Hollywood success — a success, he admitted, that had come long after he'd given up hope: "I felt like a spokesman for neglected ability . . . I feel I've landed one on the nose of the Establishment for them."

It's an interesting choice of phrase, coming as it does from a man many would consider to reside at the heart of the Establishment. His ancestors include Sir James Fellowes, physician to the forces in the reign of George III, and Rear Admiral Sir Thomas Fellowes, who served with Lord Nelson. His wife Emma is lady–in–waiting to Princess Michael of Kent; his long, steady acting career has seen him stick closely to type.

But he's an industrious chap. He writes for TV, he's an occasional columnist for the New Statesman ("The ancient second chamber is gone and, instead, we are left with a curious amalgam of record–producers and early flatmates of the Prime Minister in an orgy of patronage reminiscent of the court of James I"), he's written the book for the new Cameron Mackintosh stage musical of Mary Poppins, he recently made his debut as a film director and he's even found time to write his first novel — Snobs.

Inevitably you approach a celeb–novel with low expectations. It's largely the preserve of TV comedians who've made their pile and are now desperately seeking some late–career credibility (Newman, Baddiel, Elton, Hughes, Laurie, Fry, Edmondson, Rhys Jones, Sayle, stand up please. Coogan, Enfield, Aherne, your homework is late!). But Snobs is better than this. Perhaps one shouldn't be surprised that an Oscar–winning screenwriter can actually write, but one is.

It's the story, narrated by a 'journeyman actor', of Edith Lavery, an attractive Sloane Ranger, the only child of a socially climbing mother and an accountant. Her mother regrets her own lack of aristocratic roots but she has high hopes for breaking her daughter into society. To engineer this she sends Edith to Benenden, and then gets her on to Peter Townend's list for the opening tea parties. Her looks earn her a place as a model at the Berkeley Dress Show, and from there she's in. Except, to her mother's regret, she forges friendships with girls who share her lack of pedigree. At this point Edith takes matters into her own hands, deciding that she needs £80,000 a year to maintain the kind of lifestyle she wants. So when Charles Broughton, Earl Broughton, heir to the Marquess of Uckfield, stumblingly asks her out, she makes the most of it. After all, "the Broughtons were the very acme of the 'surviving' English family. They had reached the 1990s with their prestige and, more significantly, their estates practically intact."

Charles's mother, needless to say, disapproves, and there's a nice icy country house scene in which the engagement is announced and Edith's friends face up to the society hordes. Here, not for the first time, Fellowes demonstrates his sure eye for character: "Lady Uckfield spoke with a kind of intimate urgency, which punctuated everything she said, as if she were sharing a permanent private joke that only you (or whomever she was talking to) would understand. I think of her now as the most socially expert individual I have ever known at all well."

At the beginning the gossip columnists approve of Edith, seeing her as a latter day Cinderella. She's a good match for steady, shy Charles. He's kind and decent ("not a fashionable quality these days") but, as she discovers on their wedding night, not without some literal shortcomings: "Suddenly he heaved himself over between her legs, fumbled himself into her, thrust away a few times — no more than six at the outside — and then, with a terrific gasp to tell her that it was now, he collapsed onto her. The whole business, from the moment he had folded the paper, had taken perhaps eight minutes. Ah, thought Edith." And from that anticlimax, the interest of the novel lies in how much of herself Edith is prepared to compromise to retain her newfound position as the Countess Broughton.

Fellowes has a nice epigrammatic style. He conjures characters deftly, and although the story is slight, it's sufficient to make the reader want to turn the page. I hope that Julian Fellowes doesn't get too distracted by the other demands on his time to write another novel. He might not entirely be able to hide his glee at the privileges allowed him — as one character admits on being admitted into the Royal Enclosure at Ascot, "I have a soft spot for getting in where others are held back." But the irony is that the quality of the observations in Snobs indicate this Establishment man to be something of an outsider, which is, after all, the essential characteristic of a real writer.

Snobs is available from Amazon (UK)