Absolutely Fabulous, which is about to make its cinema debut, is a comedy about women being useless. I watched it obediently in the 1990s — mostly for the clothes — and realise now, with more jaded eyes, that I was invited to laugh only at female failure. Failure is not a bad subject for comedy — it is actually one of the best, as Edmund Blackadder and Alan Partridge and David Brent tell us — but Absolutely Fabulous is too unsophisticated to be funny, and comedy without wit is spite.

Absolutely Fabulous is based on a single sketch from Dawn French and Jennifer Saunders who were, then, the only female sketch double act on TV. (French appeared in only one episode of Ab Fab, and instead graduated to The Vicar of Dibley, a more genial — though equally self-deceptive — fantasy.) The running gag, and it is as old as Plautus is: a mother is parented by her child, who is more mature than she is. This is the original failure of Eddy (Saunders); she cannot look after her own daughter Saffron (Julia Sawalha), who becomes a dour prig. This, then, is what a real mother should be: joyless, and always in the kitchen.

Eddy, who is based upon the Jewish fashion PR Lynne Franks, is a wonderful subject for tragedy; and a complex one for comedy. She is incapable of being happy, because she has no core. She is tossed in the wind, clutching at fads (bum bags, Buddhism). Eddy is, like Franks was, rich and successful — Franks ran her own business when few women did — but you never see that on screen; you never see Eddy doing anything functional. You see only the chaos that she lives in; the fear she has of herself; the self-disgust that is the comic engine of Ab Fab. Eddy loathes her body — its bumps, its excrescences, its leaks — with a terror and commitment which, while no doubt familiar to female viewers who turn to the Daily Mail for similar torment, is pitiless. And this is why Ab Fab was always a sketch and never a great situational comedy — Eddy is the butt of the joke. Always. Unless it is Patsy.

Eddy, you see, is the functional one in Absolutely Fabulous; the enabler. The other one is Patsy (Joanna Lumley), a woman whose physical beauty initially disguises (and I imagine makes palatable for an audience, unless the producers thought it hilarious to feature a drunk who also looks like Joanna Lumley) what I can only think is the cruellest and most accurate portrait of alcoholism I have seen in popular culture. Patsy gets drunk. No — that is wrong. Patsy is always drunk. Patsy falls over. Patsy wets herself. Patsy sets herself on fire.

All this is done without nuance, without wit and without shame. Patsy Stone does not belong in comedy. Mock the people who mock her, maybe. That could be comedy. This is something else. This is the stocks.

Jennifer Saunders has said that Ab Fab is really a comedy about friendship, which I imagine sits ill with Lynne Franks, who was once, apparently, her friend. The truth, I suspect, is sadder and, again, as old as Plautus: the BBC comedy department wanted a story about women who loathe themselves, and Saunders obliged.