It started, as many things do, in a fit of pique. Venice's mayor was furious at the steady drip of rancour over the state of his city. According to detractors, the jewel of the Adriatic had become the shame of Italy, with its litter, illegal street vendors and ubiquitous dog turds. But not content with trying to clean up his own city, Massimo Cacciari had a better idea: he mounted an undercover mission to document and publicise the filth of other Italian cities, to show that Venice was no different from its peers. Cacciari said he would be posting on the Venice city website photos he took during an Easter visit to Rome's Piazza Navona and Florence's Santa Maria del Fiore church. "Those complaining obviously don't travel and should understand that they will find illegal vendors, uneducated tourists and garbage there too," said Cacciari, a former philosophy professor. He added that he risked falling out with his counterparts in Rome and Florence over the photos and he was quickly proved right. "It is in really bad taste for a colleague to bring his camera to Rome to show that we are worse than him," said the city's mayor, Gianni Alemanno. "Evidently they have time to waste up in Venice," added deputy mayor Mauro Cutrufo. "I often go to Venice with my wife but never dreamed of taking pictures of street vendors or the garbage there," said Florence's assessor for decorum, Graziano Cioni. In addition to the alleged smear tactics, Cacciari has evicted pigeon seed sellers from St Mark's Square, and is launching a "decorum" month during which bags will be distributed to dog owners to collect excrement and residents will be handed geraniums for their window ledges. "Whoever thinks the city is dirty today should think back 20 or 30 years, when it was normal to throw rubbish bags from the window into the canals," he said.