By Christian Fraser
BBC News, Rome
The Sicilian Mafia, the Cosa Nostra, is facing a revolt by local businessmen who refuse to pay protection money.
The Mafia tax affects almost every business on the island of Sicily
Until now almost every business in the Sicilian capital, Palermo, has paid off the Mafia or faced retribution.
In Italy it is known as the unofficial tax, the pizzo, and statistics prove it is an enormous drain on the economy.
But since the boss of bosses, Bernardo Provenzano, was arrested last year, the island's anti-Mafia movement has been gathering momentum.
Conservative estimates say the pizzo costs Italian business at least 10bn euros ($14bn; £7bn) a year.
But now in Sicily brave business leaders are hitting back.
At a meeting of the Sicilian branch of the employer's federation, Confindustria, members voted unanimously to expel any of their members who continue to pay the Mafia's tax.
They were voting to support Andrea Veccio, a well-known construction boss on the island who has told the Cosa Nostra he is no longer going to pay.
Since taking his bold decision he has received four death threats and two of his building sites have been sabotaged.
He and is family are now living under constant police protection.
Ettore Artioli, Vice-President of Confindustria in the south, says he applauds the decision his members have taken.
"This is a cancer which eats up too many resources. It is inflicting huge damage not only on the economy but also society in general."
"There are so many families in Sicily who want to lead an honest life and build up their businesses, but they are suffocated by organised crime," he added.
Researchers from the University of Palermo say the Mafia demands around 59 euros a month from street vendors in Palermo and up to 733 euros a month from restaurants and hotels.
Firms in charge on construction sites or road maintenance contracts can expect to pay over 15,000 euros per site.
But the deeper effect of this extortion racket is that businesses from outside the region often decide not to invest.
It means that across huge areas of the south, towns and communities are kept poor while, perversely, the Mafia and its bosses rake in a multi-billion dollar profit.