In Twentieth Century, Ben Hecht and Charles McArthur's 1932 Broadway comedy about theatre folk, a show producer on a train keeps getting plagued by passengers and staff offering him up the hopeless plays they've written, and which he wisely rejects. The same thing must happen to director Trevor Nunn wherever he goes, too. The trouble with We Happy Few - which he's now directing - is that it was offered to him by a first-time playwright he possibly couldn't refuse, his actress wife Imogen Stubbs.

While one wants to applaud producers Bill Kenwright and Thelma Holt for backing a large-scale new play in the West End - and giving it such lavish resources which, in addition to a 14-strong cast also includes a heavyweight creative team variously populated by choreographer and fight director, film producer and composer - the play itself is both over-extended and undernourished. (The payroll must be one of the biggest for a non-musical in the West End. I also noticed amongst David Hersey's lighting rig two live follow-spot operators. And, aside from set designer John Napier, there's more nepotism afoot with costumes by Nunn's daughter Elise and film by son Julian).

Between author and director - usually the most important relationship in the development and staging of any new play - there's clearly insufficient objectivity to reign in and give shape to what was a promising idea. Somewhere in here, there's an affectionate, if indulgent, play about the theatre and a troupe of all-women travelling players whose contribution to the Second World War effort was to keep the flame of Shakespeare (and Sophocles and Coward) alive around the country. (You're even given to believe this was one of the things the war was actually being fought to preserve.)

Sadly, that piece is marooned in a dense fog of expository detail and too much characterisation; jump-cuts of time and place that make it an ineffective memory play; and film reels, dramatic extracts and variety turns intended to help set the mood and tone but only serving to unnecessarily lengthen proceedings.

Based on a true-life story of the Orsiris Players (here named the Artemis Players), We Happy Few is like a primer of backstage life, complete with all those old superstitious chestnuts about the theatre like actors not wishing each other luck or saying Macbeth in a theatre (even bizarrely here when that's the play they're putting on). Much of the first act passes by in bloated extracts of plays that made me think the entire thing was in danger of turning into an elaborate version of the Mechanicals' scenes from A Midsummer Night's Dream.

The second act belatedly introduces some human dramas alongside the theatrical ones, but, despite the efforts of a strong cast led by Juliet Stevenson's Hetty, Marcia Warren's Flora and Kate O'Mara's Helen, our interest seriously wanes as the play moves towards a three-hour mark and lapses towards the overtly sentimental.

- Mark Shenton