There are some shows, not many, that are dignified even by a bad review, and this embarrassing dud from Toby Young and Lloyd Evans – job-share drama critics on The Spectator and authors of last year’s equally appalling Who's the Daddy? – is one of them.

It’s not even that members of the royal family would be upset by the defamatory nature of their representation; they would more likely feel slighted that so feeble an attempt to reveal them “as they really are” is executed with such shallow contempt for the rules of farce.

Only the residual skill of Andrew C Wadsworth’s Prince Charles, humming “My Way” with a bag of organic vegetables on his head, and the talent of Sara Crowe – investing Camilla with a heavy gait, hee-haw snort and a wonderful trick of catching up with someone’s sentence before last while gazing blankly at their present one – wheedles any sort of star rating out of me at all.

The set up? The present Queen, “the people’s queen,” has died and a commentating voice-over (the voice is the inappropriately shameless one of Toby Young himself) reports scuffles and boos at the funeral. Charles and Camilla are not popular. Back at the Palace, Prince Harry (Richard Keith) has installed a gormless Australian bimbo, Anoushka (Katie Beard), to create havoc in the minds of both Charles and Prince William (Alex Bartram) to the extent that he, aided and abetted by the oafish drunkard James Hewitt (Tim Wallers, who has an air of a lobotomised James Fox about him), will succeed to the throne.

Prince Philip (a frantically face-pulling but suavely costumed William Hoyland) is insulting foreign diplomats offstage while salivating lecherously in the direction of both Camilla and Anoushka. Everyone has no time for the bearded Archbishop of Canterbury (Christopher Birch) who is regarded as a God-denying ecumenicist with a penchant for happy-clappy hymn-singing to a tambourine accompaniment.

Beyond limp one-liners, the writing has no structural energy, the scenes no impetus or the vaguest sense of farcical architecture. A location switches, we are still in the palace. A door slams shut, the joke is unclear. Princess Diana appears in a cloud of smoke, the Archbishop in a false beard. Charles says he has abdicated, the next minute he hasn’t, the next he is syringed by a crazed doctor and thrust into a straitjacket. Philip is given a handful of Viagra tablets, the next minute he is sporting an unlikely erection that looks like a bowsprit extruding from his left knee. So it goes sadly on, finishing…oh, I can’t be bothered any more.

In Present Laughter, Noel Coward’s surrogate, Gary Essendine, advises the neophyte playwright, Roland Maule, to go away and learn from the ground upwards how plays are constructed, then write about twenty and hope to get the twenty-first produced. I am sure Young and Evans in their professional capacities (one-and-a-half acts each?) have marvelled at See How They Run, one of the best farces London has produced in years. It makes you weep to think that they might feel they have nothing to learn from Philip King and Douglas Hodge’s production, but it wouldn’t surprise me.

- Michael Coveney