ROME — For months, he had flirted with the idea of staying out of politics, but in the end former Prime Minister Silvio Berlusconi just could not resist. His statement on Saturday that he would seek office again out of a sense of “responsibility” for Italy effectively ended the mandate of Prime Minister Mario Monti, who said he would step down after Parliament passes a budget bill this month.
Mr. Monti’s surprise announcement on Saturday raised the prospect of more political uncertainty and market turmoil for Italy, Europe’s fourth-largest economy, in what is expected to be a gloves-off political campaign. But it also increased the possibility that Mr. Monti might run as a candidate — a shift from the role of an apolitical leader — who is open to governing if no clear winner emerges from elections expected as soon as February.
Three years into Europe’s debt crisis, the new developments in Italy underscored the clash between the economically sound and the politically sustainable. While Mr. Monti, an economist and a former European commissioner, has reassured investors and helped keep Italian borrowing rates down, the tax increases and spending cuts passed by his Parliament have eroded lawmakers’ standing with voters.
Mr. Monti’s grasp of economics and experience in European politics made him a power broker who took regular calls from the White House and worked with France and Spain to wring euro-zone concessions from a reluctant German chancellor, Angela Merkel.
“He’s ushered in a turning point in Italian politics and has been a major influence in Europe,” said Thomas Klau, director of the Paris office of the European Council on Foreign Relations. “He has helped turn Italy into a serious country again in the eyes of foreign investors and also many of its own citizens.”
Even if Mr. Monti decides not to run as a political candidate, his decision to step down sets the stage for a battle that pits him — a subtly ironic technocrat who attended Wagner’s “Die Lohengrin” at La Scala on Friday — against Mr. Berlusconi, who made his announcement at the training site of his soccer team, A. C. Milan.
“The war will be between Monti and Berlusconi,” said Massimo Franco, chief political commentator for the newspaper Corriere della Sera. “The moderate votes are in play, not the leftist ones.”
Although Mr. Berlusconi said he was motivated by a sense of responsibility, European leaders and market analysts immediately accused him of the opposite. Martin Schulz, president of the European Parliament, called his return to politics “a threat for Italy and Europe,” the ANSA news agency reported.
With the aid of Mario Draghi, president of the European Central Bank, Mr. Monti calmed the financial markets this year, but investors and European leaders now worry that many of Mr. Monti’s initiatives could be undone by future governments.
In an interview with the business newspaper Il Sole 24 Ore, José Manuel Barroso, president of the European Commission, said that Italy was at risk of being hit by deeper financial problems. “The next elections must not serve as a pretext for putting in doubt how indispensable these measures are,” he said. “The relative calm on the markets does not mean we are out of the crisis.”
Analysts said that Mr. Monti’s decision to step down ahead of schedule was aimed at preventing Mr. Berlusconi from running a campaign that undermined him. Mr. Berlusconi, always attuned to the national mood, even of voters increasingly weary of him, now looks poised to run a populist campaign that will criticize Mr. Monti for foisting unpopular measures on Italians and that may attack the adoption of a single currency for eroding Italian sovereignty.
Stepping down now, rather than early next year, as was expected, also puts Mr. Monti in the fray. “Monti becomes a politician at this point,” said Stefano Folli, a political columnist for Il Sole 24 Ore. “If Monti helps create a space on the ballot for an electoral alliance that recognizes the seriousness of what has been achieved, this could create a new political balance. That’s the challenge.”
Polls show that the center-left Democratic Party is likely to place first in elections, but without enough votes for a majority. But the party remains divided over which ally to choose to form a government.
Mr. Berlusconi is expected to secure enough votes to stay in Parliament and keep his immunity from prosecution in various trials, but not enough votes to govern.
“It is extremely unlikely that we will see a dynamic unfolding which would bring Mr. Berlusconi back to power,” Mr. Klau said. “So even if Mr. Monti were to leave the political stage for good, we would not go back to the political situation we were in before.”
Although Parliament has blocked some of the measures on Mr. Monti’s agenda — in recent weeks, lawmakers have proposed more than 1,500 amendments to the budget bill — the budget is likely to be approved, as is a law that requires Italy to balance its budget each year.
But analysts said that other changes aimed at improving Italy’s competitiveness were at risk. And before the end of the legislative session this month, lawmakers must also vote on a bill that would simplify the tax code, another meant to streamline the cumbersome bureaucracy and a measure that to allow the Ilva steel plant — a major economic engine for Italy — to stay open while it modernizes to meet environmental standards.
As the debt crisis has lingered, such local issues, as well as Italy’s chaotic political system, have taken on international importance.
On Sunday, Ferruccio de Bortoli, the editor in chief of Corriere della Sera, offered his review of the political drama: “The ‘Lohengrin’ at La Scala ended in applause. The Italian tragedy continues. The libretto still needs writing, so does the music. The guaranteed audience is international, but unfortunately not terribly forgiving about the cast. The curtain never falls.”
This article has been revised to reflect the following correction:
Correction: December 9, 2012
An earlier version of this story stated that the the Ilva steel plan was responsible for 8 million euro. The correct number was 8 billion euro.
