ROME (Reuters) - Prime Minister Silvio Berlusconi’s hopes of surviving a crucial no confidence motion in parliament hung by a thread on Sunday as political commentators predicted the outcome could be decided by as little as a single vote.

The 74 year-old media tycoon has gone through one of his toughest years in 2010, an “annus horribilis” of scandal and bitterness that has badly undermined his leadership and left his struggling center-right government in disarray.

A split with a group led by former ally Gianfranco Fini in July cost him a secure parliamentary majority and after months of stalemate, a no confidence motion in parliament on Tuesday seems likely to be decided by just one or two votes.

If Berlusconi loses either in the lower house or a separate motion in the Senate, he will have to resign, opening the way to either a new government appointed by President Giorgio Napolitano, or fresh elections which are not due until 2013.

But as the date labeled “B-Day” by Italian media approaches, a campaign of promises and arm-twisting has been underway to detach wavering deputies from the rebel camp and the government has been increasingly hopeful of getting through.

“I am optimistic,” Roberto Cota, governor of the Piemonte region and a leading figure in Berlusconi’s Northern League coalition partners, told SkyTG24 television on Sunday.

Political number crunchers in the media and parliament on Sunday estimated Berlusconi may just have the numbers to survive with 314 possible votes against 313 for the combined opposition.

The result remains extremely uncertain and could depend on last-minute changes of heart or outside factors such as whether any of three heavily pregnant deputies expected to vote against the government has to be absent from the chamber.

Fini declared on a Sunday talk show that even if Berlusconi does survive, he would be condemned to impotence.

“If the no confidence motion does not pass, we will have a government that’s just trying to survive,” he told state broadcaster RAI. “That’s not stability, that’s vegetating.”

SCEPTICISM

The vote will be closely watched on bond markets which are on high alert over the euro zone debt crisis and which could turn on Italy, one of the most heavily indebted countries in Europe, if the situation threatens financial stability.

Even if Berlusconi scrapes through, there is little confidence that he will have the strength to push through the kind of reforms authorities such as the Bank of Italy believe are needed to address deep-seated problems in the economy.

Italian Prime Minister Silvio Berlusconi attends a meeting with Belgium's Prime Minister Yves Leterme at Chigi palace in Rome November 4, 2010. REUTERS/Max Rossi

An alarming jump in the premium investors demand to hold Italian debt rather than benchmark German bonds last month underlined the danger, although the interest rate spread has since come back from the record levels it hit on November 30.

“However it finishes, there are grounds to be skeptical about the immediate future of the country,” Il Sole 24 Ore, the financial daily often seen as the mouthpiece of the Italian business establishment, wrote in an editorial on Sunday.

Berlusconi’s image abroad was summed up this month by a U.S. diplomatic report made public on WikiLeaks that labeled him “feckless, vain and ineffective as a European leader” and described him as being exhausted by hard partying.

At home, however, he has a well-deserved reputation for being able to speak directly to the gut instincts of many Italian voters, who have long shrugged their shoulders at reports of their prime minister’s gaffes and dalliances.

His flamboyance, charisma and the chronic disunity of the center-left opposition have put him at the center of politics ever since he first won power in 1994 in the wake of corruption scandals that overturned the old Italian ruling order.

But scandals like his connection with a teenaged nightclub dancer that took place as unemployment has crept up and problems such as the chronic garbage crisis in Naples which have gone unresolved have chipped away at his authority.

“I don’t think anything good will come of it,” Rome resident Giuseppe Rispoli told Reuters Television. “Berlusconi will stay in power because people just want to be allied to those with power and they stay for generations.”