Our New Girl, Bush Theatre

Suddenly, it seems as if the brawling youngster that was once new writing for the British theatre has grown up. Now, all it wants to talk about is the family, about having babies, and about what it’s like to be a parent. In Nancy Harris’s new play, which opened last night, the dubious joys of parenthood in an upper-middle-class family are eclipsed by the unexpected arrival of a new nanny. The inevitable question soon comes screaming at you: whose hand will be rocking the cradle?

Opening with an unforgettable image of a child in danger, the play swiftly tumbles into a scene of awkward misunderstanding. Thirtysomething Hazel is perplexed: a young woman, Annie, has arrived on her doorstep. She claims that Hazel’s husband, Richard, has employed her as a live-in nanny. They have an eight-year-old boy, Daniel, and another child on the way. And Richard is often away, working as a volunteer in Haiti, so Hazel needs a helping hand. If only he had told her what he’d done!

Richard has all the smug confidence of the alpha male

Yes, the sexual politics are clear from the off. Richard is a successful cosmetic surgeon, which funds his volunteer work, and he has all the smug confidence of the alpha male. By contrast, Hazel has given up her high-powered job as a top lawyer in order to be a mother, and now sells olive oil from home. And not very successfully. Annie watches their bickering with wide eyes and tension builds as it slowly becomes clear whose side she will take. As a picture of upper-middle-class domestic life, Our New Girl is well observed and acute.

Hazel and Richard disagree over how to bring up little Daniel, and he keeps getting confusing messages from them. On the one hand, Richard – who is seldom at home – favours the liberal approach. On the other, Hazel wants him to behave properly at school, and suspects that he has a really evil streak. You can see her point, he looks lovely but he’s a bit of brat. As an outsider, Annie both adjudicates and takes sides.

Slowly, an image develops of Daniel as a vulnerable, needy little boy who misses his father and who’s anxious about the new baby that seems to be absorbing all of his mother’s attention. One of the strong points of the play is its portrayal of the antagonism between Hazel and Richard, and of that between Hazel and her small son. There is an impressive mixture of paranoia and normal domestic wear and tear.

At the heart of the play is a secret pet, a powerful first-act metaphor of the family’s conflicts, and the subject of a scene that hums with suppressed emotion. As the story unfolds, other secrets emerge, and the shifting alliances between the three adults and one child are all structured around who tells what to who. It is an evening of lies, scars and tensions.

Harris, whose adaptation of Tolstoy’s The Kreutzer Sonata is currently on at the Gate Theatre in London, is a writer who is very perceptive and efficient at plotting, but a bit bogged down in the kind of televisual realism which confines the play within the four walls of its domestic environment. You long to hear more about the world outside this shiny kitchen. In the second half, some of the speeches are too long and the ending feels a bit off-key, but in general the plotting is terrific and the underplayed sense of the monstrous oozes nicely into the texture of the writing.

Director Charlotte Gwinner and designer Morgan Large have put together a powerful evening which clearly shows the drama of female rivalry, and of male bad faith. Hazel is an unwilling mother, and Kate Fleetwood brings out her ambiguities and uncertainties (pictured above). At times her eyes shine with hope, but more often her lip curls with contempt. As the patronising Richard, Mark Bazeley huffs and puffs through some realistic groan-provoking lines, while Denise Gough’s Annie grows from lost mouse to virago. Jonathan Teale and Jude Willoughby share the role of Daniel, an angel with dark desires. We are sure to hear much more from Harris’s sharp pen.

• Our New Girl is at the Bush Theatre until 11 February