Describing his voyage through the inferno, the medieval poet Dante included the Tuscan town of Lucca among the damned. Its inhabitants were greedy, he wrote - and the mud stuck for 700 years.

A successor has been even less kind. In the preface to an official guidebook, a local author, Cesare Garboli, said the inhabitants of Lucca were worse. Much worse.

"Almost all the sins of man, the darkest vices, money, avarice, fraud, lust, gluttony, live in the heart of the Lucchesi, frequently accompanied with a shady feeling of terror and greed."

Tourists are warned that behind the renaissance walls lies suffocating parsimony and reserve. "In Lucca people live corruption and know it more profoundly than anywhere else in the country," Professor Garboli writes.

The town is in uproar. The mayor wants to sue for libel, the book may be withdrawn and 2,000 demonstrators are expected to protest today.

A battle has erupted between the left-controlled province of Tuscany, which commissioned the book, and the town, controlled by the right, which brands it a monumental smear.

The book, Tuscany of Alps and Sea, was launched at a tourism convention in Milan two weeks ago but it was only last weekend that a member of the centre-right Forza Italia party noticed the preface and demanded action.

Guidebooks usually describe Lucca, with its Pisan Romanesque style cathedral, as one of the most beautiful spots in Tuscany.

Prof Garboli, 72, who was not born and bred in the town, said: "I confess that all this disorientates me. I really did not want to create a scandal."

He told the daily La Repubblica that his preface should be seen as a sincere effort to grapple with the fortress town's contradictions. "I wrote that it is not easy to penetrate the mysterious history of Lucca. I think that the inhabitants of this town are intelligent and have understood that."

Not all of them. "Cesare Garboli has even insulted our dessert," shouted one youth, objecting to the professor's dismissal of buccellato, a type of bun, as verging on insipid.

Fuelling indignation is anger over the 13th century onslaught of Dante Alighieri. In the Divine Comedy, a vernacular masterpiece detailing his voyage to heaven from the underworld, Dante singled out Lucca for harbouring corrupt swindlers.

The offending passage is from canta 21, verse 40: "And to that city which is full of people. Every person there is a swindler except for Bonturo; for money one says yes instead of no".

Bonturo was a notoriously sleazy Lucca politician and the reference drips sarcasm, said Simon Gilson, lecturer in Italian at the University of Warwick.

"Dante condemned almost every major Italian town but that reference is traditionally understood to mean Lucca."

Maurizio Dinelli, a Forza Italia councillor, said a supposed advertisement had condemned Lucca in the eyes of the world: "What an own-goal. We already had to put up with Dante speaking badly about us Lucchesi and now comes this book."