WHEN THE reporters in this novel are hard at work, Regrets Only is intelligent and absorbing. But when they take time off, as they seem to do often, Sally Quinn's book changes tone. It becomes a bright, flashy and occasionally amusing work of fiction that provides Washington with the same sort of glamour treatment Jackie Collins gave Hollywood and Judith Krantz offered Manhattan, Paris and Beverly Hills.

In her first novel, Sally Quinn, a former reporter for The Washington Post, has done a bang-up job of describing the glittery surface of life in the capital. Regrets Only is not a book for readers who are interested in the nuts-and-bolts workings of government; nor is it a work of fiction for admirers of exquisite language and complex characterization. Rather, it presents Washington in the frothy manner of much popular fiction.

The novel opens with Lorraine Hadley, a Washington hostess who is consummately ambitious:

"Her expert eyes passed over the flower arrangements in the living room: the chrysanthemums in fall colors, some pussy willows on the mantle, a little pyracantha in her Chinese vases -- appropriate, understated. In the dining room her round table which would serve as a buffet was draped in country-print tablecloths and laid out with contrasting napkins. Baskets lined with paisley fabric would be filled with homemade breads. A pasta would be the main course, with a salad of arugula and cherry tomatoes, another of mixed vegetables, and, of course, a ham. She always served pork -- either crisp bacon as an hors d'oeuvre, a pork roast with dinner or at a buffet, a country ham. Country ham was very salty and the guests always drank more. If they drank more they relaxed more and had a better time."

Lorraine is throwing yet another party for the usual crowd of high-toned diplomats, hot-shot journalists, heavy-hitting politicians, and a token best-selling novelist. AND WHO SHOULD arrive at the party but the four main characters. Allison (Sonny) Sterling is a blondely beautiful White House correspondent for a Washington paper called The Daily. Not only is Allison gorgeous, but she's graceful, smart -- and goddaughter of the president of the United States, Roger Kimball. As the novel opens, Allison is in the middle of a steamy affair with the also-gorgeous Desmond (Des) Shaw, Washington bureau chief for the weekly news magazine, The Weekly.

Lorraine Hadley's triumph at this particular party is her capture of the two other principal characters, who also happen to be members of the most-wanted-guest list, the vice president and his wife. William Rosewell (Rosey) Grey III is not only a heartbeat away from the presidency, but is tall, handsome, and aristocratic -- a member of one of the first families of Virginia. His wife, the second lady, is no slouch either. Sara Adabelle (Sadie) Grey is a beauty of the auburn-haired variety, an erstwhile Georgia belle with an itch her somewhat austere husband seems unable to scratch.

Regrets Only is a novel built more around situation than plot. The question of President Kimball's health -- and Rosey Grey's possible ascension to the Oval Office -- remains unanswered throughout most of the book. What occupies the reader are the amorous and professional activities of its four handsome main characters. Will the fair Allison be able to weather the internal politics of The Daily? Will she accept the offer of membership in the exclusive Gridiron club? Will she get Des away from his wife? Will she be able to reconcile the demands of her career with Des'?

And what about Sadie? Will her flirtation with the awesomely potent Des turn into a flaming affair? Will she be able to loosen up her stiff husband? Will she find meaningful work for herself or will she remain the sort of woman who can shine only in the light of her man? LIKE THE characters in the work of Sidney Sheldon and Judith Krantz, the four main characters of Regrets Only are so stunningly flawless as to be unbelievable. However, unlike Quinn, Sheldon and Krantz are natural storytellers. In novels like Scruples, Mistral's Daughter and The Other Side of Midnight, the reader is interested -- often passionately -- in what will happen to these beauties. There is a reason why Krantz and Sheldon's books invariably become best sellers; the authors are masters of the narrative thrust. Reading popular fiction should be like taking a roller coaster ride -- full of fun, thrills and irresistible momentum.

Sally Quinn is more an observer, a reporter, than a storyteller. Her story does not hurtle along, but nevertheless she has a keen eye for the detail that gives life in the fast lane its texture and appeal.

Much of this appeal, however, is pure glitz, and too much glitz can make the reader want to shut his eyes to the wearying glare. Clothes, dinner parties, and interior decoration are described over and over again until the writing seems less like fiction and more like photo captions in Town and Country. For example, what does Sadie do when she wants to write? Make an outline? Buy a word processor? No. She thinks of clothes.

"What would a writer wear? Black. That looked serious and professional. She rarely wore black, only when she didn't know what to wear. She put on a black turtleneck and black pants, just a touch of Lazlo Light Controlling Lotion, a tiny bit of eyeliner, a little mascara."

While Sadie immerses herself in Laszlo unguents, Allison is not standing around in a ratty old bathrobe:

"She chose a sleeveless silk in a cool-looking soft blue-gray -- perfect for August -- and pearls. Pearls made your skin look younger. At the last minute she had dabbed some wrinkle disappearing cream under her eyes."

Regrets Only is at its best when it describes journalism and the people who practice it. Allison and Des are not only colleagues, they are competitors, and Quinn is adept at portraying not only how reporters deal with their subjects, but with each other.

Sadie's press secretary and social secretary have an interesting conversation:

" 'It's really very simple,' said Jenny. 'There's only one thing to understand. A reporter is always a reporter first. That's it. That's all you have to know.'

" 'Ugh,' said Tilda, shrugging. 'I just don't know how people can live that way. How could you ever trust your friends?'

" 'You trust them a different way,' said Jenny. 'You trust them to be as good a professional as they are a good friend. You trust them to do what they have to do. You trust them to be honest and straight. You don't trust them to lie or cover up for you. If you're in public life you don't trust them to protect you. You trust them to protect the First Amendment.' "

This is Sally Quinn at her sharpest and most observant. She is most effective when her characters are not hidden under their wrinkle cream, when the cashmere sweaters and the chintz upholstery remain where they belong -- in the background.

Susan Isaacs is the author of "Compromising Positions," "Close Relations," and "Almost Paradise." She is working on her fourth novel.