ROME — For years, former Prime Minister Silvio Berlusconi deftly navigated the labyrinth of Italian justice, always
finding an exit — until Thursday, when Italy’s highest court handed him his first definitive sentence, upholding a prison term for tax fraud and sending Italy’s fragile government on the road to crisis.
The court called for a re-examination of a ban on Mr. Berlusconi’s holding public office, but did not reject the ban. This staved off the imminent collapse of the right-left coalition of Prime Minister Enrico Letta, which was formed to tackle Italy’s dire economy — but probably only bought it more time.
Parts of Mr. Letta’s center-left Democratic Party are reluctant to share power with a now-convicted criminal. Meanwhile, the center-right People of Liberty party looked poised to split between Berlusconi loyalists and those seeking more independence from the former prime minister in a future bloc.
“The barometer signals a very strong storm,” said Giovanni Orsina, professor of contemporary history at LUISS Guido Carli and author of “Understanding Berlusconi.” “I expect a lot of quake tremors in the next few days, but I think that the government will survive.”
The Court of Cassation confirmed Mr. Berlusconi’s four-year prison sentence, which had already been reduced to one year under a law aimed at combating prison overcrowding.
Two lower courts had convicted Mr. Berlusconi and other defendants on charges of buying the rights to broadcast American movies on his Mediaset networks through a series of offshore companies and falsely declaring how much they paid to avoid taxes.
In other cases over the past 20 years, Mr. Berlusconi, a three-time prime minister, has been convicted of tax evasion, buying judges and embezzlement, but was either acquitted on appeal or the statute of limitations had run out. (A trial in which Mr. Berlusconi is accused of paying for sex with a minor is continuing.)
Thursday’s ruling, like everything about Mr. Berlusconi, polarized Italy. Some of the former prime minister’s loyalists called it the equivalent of a judicial coup d’état, while his critics called it tantamount to Al Capone being convicted of tax evasion.
After the ruling, a furious, saddened and uncharacteristically unsmiling Mr. Berlusconi took to the airwaves of Rete4, one of the channels in his Mediaset empire, and declared his innocence, attacking the magistrates who he said had tormented him for 20 years and become an antidemocratic force within Italy.
“The sentence is absolutely groundless and violates my personal liberty and my rights,” Mr. Berlusconi said.
The man who once called himself “the politician most persecuted by prosecutors in the entire history of the world throughout the ages,” added that he would once again create Forza Italia, the party he founded in 1994. He had dissolved that party to form People of Liberty with another right-wing party. “Long live Italy, long live Forza Italia,” he concluded.
Mr. Berlusconi is widely seen as wanting to stay in public office in the hope of wielding the political influence he needs to protect his business interests.
Thursday’s ruling did not automatically send Mr. Berlusconi to prison or house arrest. It is up to the same appeals court in Milan that convicted him to formally request his arrest. Mr. Berlusconi’s lawyers can also request a suspended sentence.
Experts said that considering his age, 76, Mr. Berlusconi would more likely face house arrest or community service than prison.
Opposition politicians immediately called for Mr. Berlusconi to resign from Parliament.
Vito Crimi, a member of Parliament from the Five Star Movement of Beppe Grillo, called it “shameful” that Mr. Berlusconi would stay in public office.
In other circumstances, the ruling might have dealt a final blow to Mr. Berlusconi’s role in politics. But today Mr. Berlusconi, who came back from the dead in national elections in February, is an element of stability in the coalition government.
The government was formed to help put Italy’s economy back on track. Unemployment is 12 percent, rising to 39 percent for young people, and the national debt is close to 130 percent of gross domestic product, the second highest in the euro zone after Greece. But the government has chosen to delay a series of decisions on hot-button issues like taxes.
Even as political analysts said they did not expect the government to fall, if only because of a lack of clear political alternatives, they also said the coalition would not escape unscathed. “It’s very hard that the broad coalition government can go ahead as if nothing happened,” said Stefano Folli, a political columnist for the business newspaper Il Sole 24 Ore.
President Giorgio Napolitano, who would have to decide whether to call new elections if the coalition unraveled, urged calm. “The country needs to rediscover serenity and cohesion on vitally important institutional matters which have for too long seen it divided and unable to enact reforms,” he said in a statement.
Paolo Flores d’Arcais, the editor of the left-wing monthly magazine MicroMega, said that the Democratic Party would “pretend nothing happened,” because its leaders had already chosen to govern with Mr. Berlusconi, even if its base had not.
“For the left it doesn’t mean anything because the left doesn’t exist,” he said. “If Italy were a normal country, it would obviously be a new chapter. But if Italy were a normal country this would never have happened because Berlusconi wasn’t electable.”
Many Italians were unsurprised by the ruling.
“After dozens of trials, it was probable that he must have done something,” said Massimo Dolce, a restaurant owner in Rome.
But Mr. Dolce did not think the government would fall. “When you have a broad coalition, the ruling has less of an impact,” he said. “It won’t be an epochal shift because the conditions for that don’t exist in this country.”
He added, “It’s all very gray in this country.”