Thou shalt not steal...from the state.

That's the message Italy's prime minister wants Catholic priests to preach from their pulpits to help him stamp out rampant tax evasion robbing the state of sorely needed cash.

"A third of Italians heavily evade taxes," Romano Prodi lamented in an interview with Italy's prominent Catholic magazine, Famiglia Cristiana, widely quoted in Wednesday's newspapers.

"Why, when I go to Mass, is this issue almost never touched on in the homilies?"

Italy is struggling under the weight of Europe's largest debt pile in absolute terms. The government estimates the cost of tax evasion at 7 percent of gross domestic product, or about 100 billion euros ($137 billion) a year.

It says this is nearly double the rate of evasion in France, Germany and Britain and nearly four times that of Austria, the Netherlands and Ireland.

One Catholic leader said that while the Church strongly encouraged citizens to pay taxes, Italy's government also needed to prove to taxpayers that their money was being well spent if it wanted more cooperation.

"If at times the Church is cautious on the presentation of this issue, it is because the tax system does not always seem fair," Bruno Forte, archbishop of the central Italian diocese of Chieti-Vasto, told Italy's Corriere della Sera newspaper.

Prodi's campaign against tax evasion is one of the hallmarks of his unpopular government, and the government says it is part of the reason for a 6 percent hike in state revenues in the first half of 2007.

The premier, under pressure to cut taxes, suggested too many Italians still lie on their tax returns. He questioned out loud whether it was possible that only 300,000 taxpayers -- out of a total 40 million -- made more than 100,000 euros a year.

"To change this mindset, it's up to everyone, starting with the teachers, to do their part ... the Church included," Prodi said.