Guess what? Teachers can be as bad as their pupils. Even really bad pupils.

Who would have thought it?

This is the premise of the Richard Davidson play Badnuff, set in a pupil referral unit, at London’s Soho Theatre.

In the Badnuff PRU, it is not just the pupils who lie, cheat and scream.

But there is a flaw in this attempt to shock. Teachers, the Channel 4 series, built its reputation on seeing staff swear, drink and sleep with each other. Familiarity has tempered surprise. Badnuff lacks originality elsewhere.

Much of the plot trades on the relationship between two teachers at the unit. There is Tom, the cynical head, whose enthusiasm has been worn down by unresponsive pupils. And there is Maggie, keen for her charges to get in touch with their feelings, but unwilling to accept Tom’s feelings for her.

This face-off between old and young, cynical and relentlessly positive is not new. Similarly, the pupils themselves are outlined through a series of tired characterisations. So Jay, the silent new girl, has a dark, dangerous side. Brendan, the sexual aggressor, was abandoned by his parents as a child. And Lanny, the livewire 15-year-old prone to bouts of volanic anger, cradles an unwanted baby doll in his arms.

The six-strong cast all offer strong performances. In particular, Michael Obiora, as Lanny, is sparkily believable. And the play is enjoyable enough, and never drags.

But the audience is left wanting more than its would-be shocking revelation: that sometimes bad kids can be good, sometimes teachers can be bad, and at heart everyone just wants to be loved.

Badnuff runs until April 17. Box office: 0870 429 6883