The play of the film of the novel

You've heard of the film of the book. And the book of the film. And the TV tie-in. And the tie-in book of the TV series. Well, opening at the National Theatre tomorrow night is a more elaborate and infinitely more distinguished spin-off phenomenon along those lines. Remembrance of Things Past constitutes the theatrical realisation of the screenplay - never filmed, but once performed on radio - of Proust's great novel. The original movie treatment was by Harold Pinter and, infuriatingly, the funds were never found to commit it to celluloid. So he has now had the inspiration to collaborate with a theatre director on a stage version of the film version of the book. Get your head round that.

You've heard of the film of the book. And the book of the film. And the TV tie-in. And the tie-in book of the TV series. Well, opening at the National Theatre tomorrow night is a more elaborate and infinitely more distinguished spin-off phenomenon along those lines. Remembrance of Things Past constitutes the theatrical realisation of the screenplay - never filmed, but once performed on radio - of Proust's great novel. The original movie treatment was by Harold Pinter and, infuriatingly, the funds were never found to commit it to celluloid. So he has now had the inspiration to collaborate with a theatre director on a stage version of the film version of the book. Get your head round that.

Getting her head round it and over it and right inside it is Di Trevis. Not only is she staging the piece (at the Cottesloe), but her name now appears up there with Pinter's on the script. I liked her the moment I met her in one of the offices at the National. For two reasons. First, she was sitting, as I entered, surrounded by the numerous press cuttings that have been spawned by the dramatist's 70th birthday, and quite unguardedly she declared that it's wrong to want to sanctify great artists. Already, she had almost made it on to my Christmas-card list.

Then, secondly, she scored masses of points with me by not having bothered to check in advance which journalist had come to interview her. "I'm sorry, I don't who you are," she smiled. And when she found out, she kept her cool - better than I did, actually, because I am all too conscious that I'm one of those critics who, back in 1988, took a certain amount of glee in trashing her troubled RSC staging of Much Ado About Nothing. It was a traumatic episode for her, as she has outlined several times in print.

Trevis is certainly nothing if not intrepid. To collaborate with Pinter on anything would, you'd guess, require, in the accomplice, a heart of oak. But there's a special reason why working with him on Proust would be daunting. The dramatist has written that the year - 1972 - he spent engaged on reading and adapting A la recherche du temps perdu "was the best working year of my life". And that's because he wasn't just working on Proust: Proust was working on him and helping to shape Pinter's own artistic development.

Proust has been a fertile influence on many artists. One of the best commentaries on the great novelist is, for example, a series of radio plays that Pamela Hansford Johnson wrote in the Fifties. These take the whole glittering, decadent galÿre of Proust's world - the arrivistes and the aristos, the dreyfusards and the anti-dreyfusards, the women who are not really women and the men who are not really men - and propels these figures into later times, with the most revealing results.

For example, she seizes on one of the novel's greatest comic creations, Madame Verdurin - a garrulous arch-snob and tuft-hunter who requires her salon habitués to think of themselves as a sect - and deposits her in the Vichy France of 1941, entertaining the Nazis. It gives the character a stunningly bracing afterlife.

On the face of it, Pinter's approach might seem to be very different. He wrote in the preface to the 1978 published version of the screenplay that, "We knew that we could in no sense rival the work. But could we be true to it?" The answer to that question is yes, but in a rather spooky way, for in the process of adapting him, Pinter, as it were, inseminates Proust with his own future writing as a dramatist.

Certainly, you feel that the novelist would have a wonderful time at any production of Pinter's Old Times. Indeed, you could argue that he would be proud of it. For that play, with its triangular relationship between husband, wife and a female friend from the wife's past, brilliantly heterosexualises the male fascination with and fear of lesbianism that permeates large tracts of A la recherche. Deeley, Kate and Anna are continuations in a different key of Marcel, Albertine and Andrée.

You can't, however, readily imagine Proust rushing out to buy a copy of The Whole Woman or, even if he had managed to procreate, putting in a bid for paternity leave from the cork-lined bedroom where his novel accreted. So what's in it, and in him, for Di Trevis, who is a woman with a child and a husband (the composer Dominic Muldowney, who has written the music for this event)?

"I've never asked myself that before, so I'm talking completely off the top of my head here. But I would imagine it's something to do with his solitariness and his outsiderness." Women can identify with that, particularly creative women with small children who, according to Trevis, "feel exiled whether at work or at home".

Living in France in the late Eighties, with a babe-in-arms, Trevis started to read Pinter's screenplay, and this gave her a way into Proust. Then, in 1997, Peter James, who runs the London Academy of Music and Dramatic Art, provided her with "the perfect work rhythm" by asking her to develop a project with his students: four mornings a week for four and half months. It was there that her staging ideas for the screenplay began to bud.

But has women's love of Proust, I ask, anything to do with the fact that at some level he wanted to be a woman? "I think," Trevis replied, "that he wanted to create anew in himself an idealised mother figure. He yearned to be that for himself, that gave the goodnight kiss that he craved from her." So, not a simple man.

There's a section in Roger Shattuck's new book on Proust (Proust's Way) called "Filming the Unfilmable", where he manages to be condescending even about Time Regained, the imaginative movie of the novel by the Chilean director Raul Ruiz, released at the start of this year. In my view, the genius of Proust is that, living in the early days of cinema, he managed to supersede that art form, his prose taking one down (as film can sometimes give the illusion of doing) to the ocean-floor of consciousness better than any writer who has yet lived, including Shakespeare.

But if Ruiz's movie exploits cinema's ability to create a film-within-a-film effect, Pinter and Trevis demonstrate, in their stage adaptation of a screenplay, that theatre has one big advantage over film. In this respect: theatre can include filmed images, but film can only include filmed theatre, not the real McCoy. I cannot think of a better use of the Cottesloe than turning it into a laboratory where the limits of three ways of perceiving the world rub up against each other and, with any luck, take us to unfamiliar places.

The National, in the current phase of its evolution, tends to arrange things either very imaginatively indeed, or with a depressing poverty of imagination. It has not done well by Oscar Wilde and his centenary, but for Harold Pinter and his 70th-birthday celebrations, it has - merely in expediting this absolutely fascinating affair - turned up trumps.

What with Patrick Marber's inspired revival of The Caretaker in the West End, and this Remembrance of Things Past - which, if it is as good on stage as on the page, will be a five-star event - his 71st year is turning, as is only proper, into something of a annus mirabilis for Mr Pinter.

'Remembrance of Things Past' opens at the National's Cottesloe Theatre, South Bank, London SE1 (020-7452 3000) tomorrow