The city that went to war on advertising

Sao Paulo has banned billboards, and residents are using a hotline set up by the Mayor to report any and all offenders

Stealthily, cleverly, implacably, the officials of Sao Paulo – its 20 million inhabitants make it one of the world's largest cities – are after their prey. Since the first day of 2007, morning, noon, night and at weekends, Argus-eyed, they wait and watch for it on foot and in their vehicles. Their weapon is the Lei Cidade Limpa, the Clean City Law.

They are there, downtown among the tall, undistinguished buildings that cluster round the entrancing Copan Building, the world's most beautiful skyscraper, designed by Oscar Niemeyer. They lurk on the eight-lane urban motorways. Their people keep a watch on the shopping arcades. They keep an eye on the miles and miles of dreary suburbs and the anthills of the slums along the polluted River Tietê as it stinks its way past the race course.

Directly they see their quarry, they pounce. It can't camouflage itself; that would go against its nature. It is after all, advertising, and Sao Paulo is the first city in the world to ban it. Billboard advertising has, simply, been outlawed. Eight thousand hoardings have been done away with so far, with more to go. Those who disobey the law can be fined more than £3,500 per offending site. In its first year, the law brought to the city nearly £15m in fines.

Today Publicidade, as we call the spirit of billboard advertising in Sao Paulo, is fighting for her life in the political jungle of Brazil. So bruising is the fight over legislation in Brazil that, the other day, President Lula da Silva despairingly remarked that the gap between what he wanted to do and what the politicians let him do was as wide as the Atlantic. He added: "If Jesus Christ came here and Judas had a vote in any political party at all, Jesus would have to get Judas on the phone to clinch a deal."

The admen tried everything to stop the measure before the vote was taken by the municipal council in Sao Paulo. They forecast – mendaciously – that it would lead to massive unemployment, but the law was passed on 26 September 2006 by 45 votes to one. Their trade association, Sepex, took the Mayor to court, arguing that he was attacking free enterprise in an unconstitutional way and that only the Federal Congress in Brasília had the power to legislate on advertising matters.

At first, they seemed to be in with a chance and got a postponement of the application of the law. But the STF (the Federal Supreme Court) was impressed by the big majority with which it had been passed and by the way citizens were being given a part in making it work. The STF judges disagreed with the lower court saying it was fully constitutional and indeed enjoyed "the highest degree of public interest, seeking as it does to promote the public good essential for a better quality of urban life".

Dalton Silvano, an adman and the sole opponent in the council vote, claims that the city is joyous no more. He admits his side has lost a battle. "But we haven't lost the war," he claims, a little unconvincingly.

It could be said Publicidade has already died the death of a thousand cuts. Hoardings on the side of buildings have been painted out. Shop fronts are under tight control, with advertising held to fierce limits of a proportion of their façades. The sides of buses are clean – not for these vehicles polemics for and against God, no pretty girls smiling as their sip their sugary, gassy colas. Nothing but the neat coat of arms of the city. The trouble for Publicidade has always been that the ban on her has been very popular.

The Mayor, Gilberto Kassab, revels in the popular acceptance of his measure and his city's position as the world's first metropolis to crush the admen and the big transnationals which screamed so loudly as the ban was introduced in 2007.

He set up telephone hotlines where citizens could report instances of advertisers breaking the law. "Some days, we had 3,000 calls on those lines," he says contentedly. Kassab says that Sao Paulo's lead is being followed by Buenos Aires, and some European cities – but not London – have sent missions to have a look at his city's experience. Regina Monteiro, a colleague, says: "The ads filled our eyes with nothing."

Now Mr Kassab is trying to improve the city's air and water and cracking down on noise pollution. The disposal of sewage is a major challenge in a city where developers did not feel they had any responsibility for linking their buildings to a sewage system. Millions of the city's inhabitants use septic tanks, and raw sewage is fed unceasingly into the reservoirs.

Yet still Publicidade rises to her knees, groggily now, denying to the last she will be exterminated. But the only thing the admen can look forward to is a fight with Mr Kassab about how many bus stops and bus shelters are going to be allowed to carry small ads. "Before the advertising ban," says Jorge Wilheim, a well- known architect and town planner, "Sao Paulo was chaotic and ugly. Now it's just ugly." But the sandwich men legally carrying their messages on their backs are laughing. They are doing a good trade.