Adult Supervision, Park Theatre

It's often a sign of a good drama when, as it concludes, you find it hard to tell which character you dislike most. And so it is with Adult Supervision - all the way through, first-time playwright Sarah Rutherford skilfully manipulates your allegiances, causing your sympathies to shift and shift again until there is no one left to be redeemed.

The action of this play takes place on the night of the US election in 2008. Natasha, an uptight, anxious woman with a shiny, too-perfect hairstyle, is hosting a results party for what we assume are a group of her friends. However, it soon becomes clear that three of these four women barely know each other. With the exception of her best friend Izzy - who is played with flair by The Thick Of It's Olivia Poulet (pictured below, on the right with Jacqueline Boatswain) - she has invited her guests because they are "mothers of children of colour".

You're left wanting something bigger, more substantial, more lasting

It would be an understatement to say that race is the driving force of this drama. Each woman has a different background and family set-up affecting her views on it: Natasha (Susannah Doyle) and her husband, who are white, have adopted two children from Ethiopia; Mo is married to Vince, who is black, and is anxious that their children should be called "mixed race" and nothing else; Angela, a heavily pregnant black woman, is married to Owen, who is white. While they sip "Obamatinis" and nibble on Natasha's Ethiopian finger buffet, their other halves and older children are spending the night camping on the nearby common.

Into this contrived little party are lobbed various other contentious issues associated with parenting, divorce, adultery and extremism. Then, just to keep things lively, a game of Truth or Dare is instigated. Rutherford's script is tight and precise, and she's very cleverly skirted the boundaries of acceptability and taboo. By exploring, for instance, whether it's offensive to call a black woman beautiful and "exotic", or to touch a mixed race child's "amazing" hair, she winds both her characters and audience into such a state of nervous cringing that the laughter some of the best lines provoked bordered on the hysterical.

But behind the clever sallies, the drama is sometimes a little thin and occasionally borders on the farcical, such as when Tash destroys her son's teddy bear with a large knife because he wouldn't settle down to go to sleep. It should be a poignant and shocking moment, but it just seems awkward and vaguely amusing.

As the play comes to a close, you find yourself grasping for a hint of a deeper message. There are lots of witty observations about middle class guilt and British multiculturalism here, but as Obama sweeps to victory and the characters embrace to the strains of will.i.am's "Yes We Can", you are left wanting something bigger, more substantial, more lasting. Five years on from that historic election, the political parallels are uncanny.

• Adult Supervision is at the Park Theatre until 3 November