First Night: Cinderella, The Old Vic, London

Fry favours the filth in tired foray in pantomime

"Let them eat cake", was the lofty cry of Marie Antoinette. "Let them shriek 'cake!'" seems to be one of the ground rules of Cinderella, the eagerly awaited Old Vic pantomime scripted by an obscure, semi-educated recluse called Stephen Fry. It's a c-word and it has four letters but my goodness it isn't a verbum non gratum as Fry himself might put it in this Yuletide show. The endearing, gay (natch) Buttons (Paul Keating) tells us that it's a law of Pantoland that if you hear anyone mentioning "cake", you have to shout it back. His word is our command.

Actually, I think that Fry missed a trick here. His script is playfully determined to put the "rude" in "erudite" and there's a lot of rather leaden larkiness. In fact, two adults asked me during the interval the meaning of "inanition" and "accidie", so you can imagine how rib-tickling the kids found those particular gags. But it struck me that he could have intrigued the youngsters if he'd dropped in some examples of "cake" tricksily concealed strung between two words as in "OK, clever clogs" or "that was a bit risqu, cock!". Did you hear "cake" in those phrases? Oh no, I didn't. Oh, yes you did.

The English are suckers for all things monarchical so it's good that panto at this address has become a stomping ground for lovable old queens. But where Sir Ian McKellen strutted his cross-dressed stuff onstage, if Stephen Fry is spending this Christmas in drag, it's in the privacy of his own home. His role here is purely authorial, though "impurely" might put it better, for his script, premiered in Fiona Laird's garish, unsympathetic production, is a non-stop smut factory. Don't get me wrong. I think it's great that Buttons and Dandini get it together and I quite liked the shower scene involving Joseph Simmons's heart-throb hunk of a Prince.

But there's a difference between good, clean, relevant filth (as when Mark Lockyer's Ugly Sister compliments the Prince on the way he hold his balls) and relentless, gratingly contrived gags about, say, vibrators and dildos (the Stepmother is "left to her own devices..."). Even Madeleine Worrall's likeable, throaty Cinders is shown waking up from a couple of erotic dreams with heavily engineered puns on her lips. Pauline Collins is a charming delight as an East End Fairy Godmother who can't believe how slow Cinders is to twig to her identity. Nice, droll Sandi Toksvig is womanhood's answer to Stephen Fry as the narrator. However, the Ugly Sisters (called Dolce and Gabbana why not Trinny and Susannah, same rhymes?) are too lewd to be amusing; the songs and choreography are frighteningly feeble. The Prince's hunt for a wife at the ball becomes "The Princess Factor 2007". But we don't see the competition and we don't get to vote. All we're presented with are the results.

Isn't that strange for a show which promised us lots of "interactivity" but which turns out to be so essentially soulless that it could have been written by a cannily programmed computer.