Battle to save London's most disgusting landmark

One can only imagine the Mayor of London has his eyes on the Trafalgar Square guano concession. Earlier this week Ken Livingstone was reported to have threatened to take control of one of London's least lovely landmarks, after Westminster Council expressed reservations over plans to pedestrianise and enlarge the square, but looking at it on a hot weekday afternoon it isn't easy to see why he would want it, aside from a desire to exploit the mineral rights.

One can only imagine the Mayor of London has his eyes on the Trafalgar Square guano concession. Earlier this week Ken Livingstone was reported to have threatened to take control of one of London's least lovely landmarks, after Westminster Council expressed reservations over plans to pedestrianise and enlarge the square, but looking at it on a hot weekday afternoon it isn't easy to see why he would want it, aside from a desire to exploit the mineral rights.

A council sign by Nelson's Column warns of "Slippery Surfaces", a discreet reference to the fact that, whatever else it is, the square is a vast convenience for London's pigeons, who can load up on corn at the public's expense, and dump faecal ballast at the same time.

Across from the pigeon feed stall in the south-east corner sits its human equivalent, an ice-cream van, adding its hot breath to the exhausted air of the traffic-locked piazza; on the roof a grubby thatch of pigeons take time out from perching on the corn-stuffed fists of tourists who can't really explain how they've ended up in this metropolitan U-bend - a swill of henna tattooists, hawkers (anyone for a novelty lighter with a flame emerging from a topless woman's nipple?) and Eastern European refugees selling bootleg copies of the Big Issue.

"Too many pigeons," says one American tourist, who is busy videoing his young son's communion with a swarm of the city's airborne rats, "I think they oughta outlaw this kind of thing." But this kind of thing is largely why they come - apart from the chance to scale Landseer's lions and use Charles Barry's fountains as an impromptu lido. Nearby, Caroline Sergeant, a British visitor, watches her two young children feed the pigeons with a mix of maternal affection and hygienic anxiety. "Dreadful," she mouths silently, when I ask her opinion of the square, reluctant to tarnish their pleasure. And she isn't very optimistic about pedestrianisation either: "It'll just make it worse, won't it?"

Westminster Council shares this view - Simon Milton, the council leader, arguing recently that pedestrianisation hasmade Leicester Square a "nasty and brutish" place, especiallyafter dark. At present Trafalgar Square is a place where legality and licence are in an uneasy truce; a policeman, fresh from quelling a squabble between two portrait artists, explains that his jurisdiction formally stops at the edge of the pavement. The square itself is private property and the responsibility of its owner, the Department of the Environment, which has not found it easy to control the entrepreneurial vigour of the street traders. The policeman admitted that a Hobbesian criminal justice system regulates the highly profitable ice-cream pitches, its workings largely invisible to the authorities.

But, as Euan Blair found, for anyone seeking a brief respite from verticality, there is really no contest between Leicester and Trafalgar. The former may have higher levels of street crime - one symptom of which is the electronic sign warning that undercover police are at work - but it has grass and trees and some vestigial efforts at civic amenities. Leicester Square also has other things to do besides encourage vermin - unless you take a caustic view of the buskers who line its northern side, fattening the crowds for the pickpockets. The other day a feisty French clown opened his act by pretending to whisk a bra off a bemused Japanese tourist, instantly stealing the crowd from a man doing football tricks on one side and a living statue on the other - dressed as a city gent and pressing hard for entertainment's equivalent of Absolute Zero.

Whatever you think of it, Leicester Square has a life that Trafalgar Square currently does not. The awkward truth may be that both the Mayor and Mr Milton are right. Pedestrianisation is unlikely to solve all of Trafalgar Square's deficiencies as a place of public resort (architects' drawing-board fantasies of an elegant Mediterranean passagiata never quite work out in gritty reality). But it should reconnect it to the touristic mainland, turning a granite-flagged island into an accessible promontory. That makes it just as accessible to thieves and drunks as to innocent tourists, but the problems of success are surely preferable to the problems of urban failure.