PAT BARKER achieves immediate distinction with Union Street. Into the jaded, overcrowded, imitative world of first novels she has introduced a book that is at once mature, faultlessly constructed, and daring enough to take as its subject life itself in the most elemental sense: poverty, sexuality, rape, pregnancy, abortion, marriage, birth, sickness, prostitution, decrepitude and death, all interlocking. Where a less gifted writer might have fallen headlong here into the double trap of stridency and mawkishness, Pat Barker keeps her story so free of abstract moralizing that its final effect is close to visionary. It is not surprising to learn that she was one of 20 "Best of British Young Novelists" selected by The Guardian in 1982.

Not that Barker's material strikes one, at first, as likely to yield visions. "Union Street" is a tough, working-class street in an unidentified steel town in England's blighted industrial northeast. It is winter, 1973. Strikes and lay- offs gather steam. The city is blackening around its own economic decay. Union Street struggles to hold its own between the utter dereliction of the streets near the river and the mockery of those bordering on the park, where the "big, substantial Victorian houses . . . had preserved their air of smug assurance into a more violent and chaotic age." The novel tells the stories of seven women who live on Union Street and whose lives intertwine with each other's, and the city's, in such a way as to form a single representative life. (American readers may be struck by the structural similarity to Gloria Naylor's The Women of Brewster Plac, in which black, working-class, female experience is also dramatized in the stories of seven women living on a decaying street in a nameless, industrial, northern--albeit American--city.)

Union Street is divided into seven parts, each named for a woman, beginning with 11-year-old Kelly Brown, who is raped and then half-abandoned, and ending with dying Alice Bell, who takes refuge in the streets sooner than face the old people's home. Certain incidents are repeated from different angles in two or more of the stories, creating an uncanny illusion of depth or, better, inside knowledge. Thus, the dead baby which Kelly finds in some rubble near her home, "as red and translucent as a ruby" with "his sealed eyes and veined head," is already familiar to us when he is finally identified in Iris King's story some 150 pages further on. " 'It was dead, Mam, wasn't it? 'It was never alive, flower. It's not a baby, you know.' " We are taken into the life of the street as into the various chambers of a heart.

Union Street is emphatically not the kind of book which you might casually recommend to your mother or neighbor as a relaxing read. The book's vision, if it is a vision, is of a life brutal and scabrous in the extreme. Lives such as these, it seems to say, would be falsified by the modesty of literary circumlocution. So the material is almost unremittingly sensational. Certainly, if you are not shocked by the marvelously frank speech, the frequent exposure of genitalia (with varying degrees of distaste), or the spattering of excrement and sperm and phlegm, you will be shocked by the abuse of children, old people, simple girls and deformed men--that is, the systematic creation of victims--which, the book suggests, this depressed life will breed. A great part of Union Street's strength lies in its completely unsentimental characterization of the English working classes.

And yet, miraculously, Pat Barker also sees in each of these seven lives a flicker of affirmation or, in a theological sense which she does not at all press, salvation. There are two ways in which this spirit of hope is sustained throughout the book. One is the irrepressible humor which keeps bobbing to the surface of each grim life. Take, for instance, the exchange between young, pregnant Joanne Wilson and old Mother Harrison, met "picking her path between piles of dog muck" in the alley behind Union Street. Mrs. Harrison is absorbed in her daily task of collecting with a pair of silver sugar tongs the french letters left over from the activities in the alley the night before; she claims to use the contents to quicken the flames of the Mission fire. " 'Aren't you afraid of catching something?' 'The Bad Disorder? No. The Lord looks after his own. Anyway, I never touch them.' She held up the tongs and smiled. 'George is the one for sugar in our house.' "

The other life-sustaining element in the novel--and the one in which its visionary quality inheres--is its recurring use of the natural world as a metaphor of grace. The most striking instance is the vision experienced separately by the child Kelly Brown and the old woman Alice Bell: the winter-bare tree in the park, transformed by birds and light into an image of the possibility of life's transformation. "And now when she looked at the skyline she saw that one tree stood out from the rest, its branches fanned out, black and delicate, against the red furnace of the sky . . . and when she looked more closely she saw that the tree was full of birds, clustering along its branches, as thick and bright as leaves. And all singing. But then, as she came closer still, as her white hair and skin took on the colours of blood and fire, she saw more clearly, and in a moment of vision cried. It isn't the birds, it's the tree. The tree is singing."

Pat Barker's Union Street is a singularly powerful achievement. On the evidence of this one book, her most promising quality is, perhaps, the unusual combination of a strictly naturalistic style with a genuinely poetic sensibility. It will be very interesting to see what she does next.