What do we want for Christmas from the National Theatre? Preferably something with magic and mystery on the lines of Peter Pan or The Wind in the Willows. But this year we get a middling British musical by George Stiles and Anthony Drewe that, however colourfully presented, drains Hans Christian Andersen's original story of its limpid grace and beauty.

The show is intended as a hymn to nonconformity, yet nothing could be more resolutely conformist than Stiles's music and Drewe's book and lyrics, which pay the usual obeisance to the cliches of showbusiness. You see this early on when Ida, the duckling's mum, and a moorhen join in a brassy number that could have come straight out of Gentlemen Prefer Blondes. And in the second half a bullfrog cheers up the persecuted duckling with vaudevillian shtick and a routine that ends up as pure Busby Berkeley. I know we are all Americans now, but you would think a children's show at the National could transcend the tired tricks of Broadway and Hollywood.

But one wonders who the show is aimed at, since it is decked out with theatrical camp and dubious double entendres. Jasper Britton's predatory Cat is turned into a leering, epicene bird-molester who appears round doorways crying: "Hello ducky." Meanwhile Lowbutt and Queenie, a co-habiting hen and pussy, are played as a bickering couple straight out of The Killing of Sister George: at one point Lowbutt tells Queenie:"It's as much as you can do to get your flap open." Try explaining that one to the children.

There are some nice moments in Julia McKenzie's picturesque production, not least a climactic snowscape evoked, in Peter McKintosh's design, by a cascade of white umbrellas. Whether it is a good idea to cast a young black actor, Gilz Terera, as the ugly duckling is a matter of taste; it makes for some sticky moments early on when he seems to be shunned purely on grounds of race. But he acquits himself well, as do Beverley Klein as his doting mum, David Burt as his heedless father and David Bamber as a pompous, Captain Mainwaring-style goose. The beauty of Andersen's story is that the hero is allowed to rejoice in his physical translation. Here we get a stick-on moral - "Just believe in yourself, don't be left on the shelf" - that epitomises the show's journeyman banality.

At the Olivier (0171-452 3000) until March 25