Stephen Bayley: What was so wrong with the empty plinth?

This has been a pleasant curiosity of London life for many years, but a busy committee has been active on our behalf, redressing a loss that never was. After three sculptures were temporarily sited on the plinth between 1999 and 2001, a scary-sounding commission was charged by Ken Livingstone, Mayor of London, with abhorring the vacuum atop the plinth. Positively East German in its thoroughness and insensitivity, The Empty Plinth Commission (or whatever it is called) proposed a series of sculptures. The first of these, the monumental treatment of a dis- abled, pregnant, female nude was, quite literally, unveiled this week to, quite predictably, minor controversy.

Alison Lapper Pregnant is not art. So what is it? The title is a bit of a giveaway: it is conceived as a product, or possibly even a brand. Perhaps its perpetrator, Marc Quinn, who once prettily modelled his head in his own blood, has a whole line to roll out, as we say commercially. We can have "Alison Lapper Asleep", "Alison Lapper Cooking", "Alison Lapper Watching Telly". The ALP has another function, too.

True, the ALP concept lacks the focus-grouped essentials of ethnicity and lesbianism, but they can be fixed in a future model. For the time being, a disabled, nude, single mother inserted in a famous public space allows the mayor to tick a lot of boxes on his dog-eared, laminated political questionnaire.

It has been said that political correctness is simply a version of good manners, but I hope it is not bad manners to condemn this dire tripe. Yes, I know that the actual Alison Lapper is a brave, humorous and stylish individual (an artist, who lives in a Sussex cottage with her son), but that does not prevent Quinn's sculpture of her being brainless kitsch.

Yet even the brightest minds have been fazed by the bracing whiff of correctitude swirling around the plinth. Whether, like the normally sensible Charles Saumarez Smith, director of the neighbouring National Gallery, you find the ALP "beautiful" is a matter of opinion. The crudeness of Quinn's 3.5m conception is fact.

Kitsch was memorably defined as what is left when the anger leaves art. Despite the pseudo-defiant posturing about disablement and the wickedness of objectifying female bodies in the conventional way, the ALP is lazy, obvious, witless. Significantly, it was made in Italy by craftsmen used to handling marble (Quinn's own role was nurturing the "concept" and making some casts off the living body), thus the ALP has about it something of the feeling of Mussolini's doomed ideal cities with their muscular fascist athletes and corn-gathering maiden.

A feeble one-liner, predictable and crude, offering neither originality, insight nor exciting confrontation, it is very likely that Alison Lapper Pregnant will become very popular. But then you have to consider the nature of Trafalgar Square itself. Once the emotional centre of a vast imperium, Livingstonian decrees have turned it into a hopeless piazza occupied by listless tourists, hemmed in by a girdle of open-top buses. Oppressive traffic management schemes now make it more difficult, dangerous and costly for resident citizens to cross the square whether they are using foot, bike, bus or taxi.

Yet from supporters of the ALP there will be blather about the importance of "public art". The reason we have no authentic public art is because we have no authentic public spirit. It is easy for Ken Livingstone to count off on his fingers what the ALP does for his own stale notions of correctitude. It does very little worthwhile for London's townscape.

But now that The Empty Plinth Commission has done its work, perhaps its energetic members could be reformed to tackle one of the real problems of life in the capital: the lowering squalor of the streets. The mayor abhors empty plinths, but he seems to have a blind eye for insolent road works, neglected buildings and mess. But that's the thing about public art, to enjoy it, you don't need a good eye.