Daniel Radcliffe might be said to have established the pattern by taking on a daring stage role in Equus far removed from his image as the screen's Harry Potter. Now Anna Popplewell, who plays the goody-goody heroine in the Chronicles of Narnia films (pictured), is making a similar move by starring later this month in a new production of the controversial play Spring Awakening in which she plays a girl made pregnant at the age of 14. While the extent of her public exposure will not be as great as the in-the-buff Daniel (presumably), she will nevertheless find herself doing and saying things on the Oxford Playhouse stage that would cause her Narnia character Susan Pevensie to shudder in horror.

Rape and homosexuality also figure prominently in the play, by Frank Wedekind, a German writer long recognised as a pioneer in advocating the need for sexual honesty. Completed in 1891, it was not seen in Britain until 1965, and then in a version bowdlerised by the Lord Chamberlain. Obvious targets for his blue pencil were a scene of mass masturbation in a school dormitory and a graphic embrace by two boys in an orchard. An early production, following the end of that censor's fell influence, was seen in Oxford 40 years ago.

Anna, an English student at Magdalen College, plays the leading character of Wendla Bergmann who is torn between clinging to her childhood and embracing her adult future. She says: "The world Wedekind represents is certainly a very different one from Lewis's Narnia. Wendla is a really interesting character, precocious and outgoing but caught in the confusion of adolescence. She doesn't really understand what sex is and, in the repressed society she is brought up in, the adults around her are reluctant to explain.

"Studying this character has been a real challenge and comes with the added difficulty of having to reach the same emotional intensity every night on stage. It's very different to working in film."

Though the part will give 19-year-old Anna her debut on the Playhouse stage (from May 26-31), she already has some experience of theatre in Oxford. Last year, she won the Cuppers Prize for Best Supporting Actress in the student production Five Kinds of Silence and also played Lady Macbeth at the OFS Studio. Her second Narnia film, Prince Caspian, has already opened in the US and will be shown on British screens from late June.

With a play of such obvious interest to children, one wonders what efforts will be made to attract school parties. (A possible supporter in this might be the poet Michael Rosen, the present Children's Laureate, who as a student at Wadham College in 1968 directed the aforementioned Oxford production of the play.) A move to offer cut-price seats to schools was rejected by the Inner London Education Authority when the National Theatre presented the play in 1974, in the same translation being used in Oxford, by Edward Bond.

This is a production I remember well, having reviewed it when it toured to Oxford in July of that year. It featured a fine cast, including Beryl Reid, Cyril Cusack, Michael Kitchen and Jenny Agutter. Anna's role of Wendla was taken by Veronica Quilligan and that of her teenage lover Melchior by Peter Firth. There was potent stage chemistry between the pair, who later in the year went on to star (for the NT) in perhaps the finest production of Romeo and Juliet that I have seen. My verdict on Spring Awakening was that it possessed considerable relevance to a modern audience, though perhaps not in the way one might imagine. "The sexual content seems almost tame in the supposedly permissive seventies, when Wedekind's argument that there should be greater freedom and openness about sex has been overtaken by events. Its real value seems to me to lie in its questioning of the other ways in which society represses its children and, in particular, our system of education: corporal punishment, the competitiveness of examinations."

I wait with interest to see how the play is judged in 2008.