(CNN) -- Italy's parliamentary elections kick off Sunday, with polls suggesting the center-left -- led by Pier Luigi Bersani -- is on track to defeat controversial three-time prime minister Silvio Berlusconi.
But Berlusconi's rise in the polls in recent weeks, combined with widespread public disillusionment, means that nothing about the race is a foregone conclusion.
Who are the candidates?
The two-day election is a four-horse race between political coalitions led by Bersani, Berlusconi, outgoing premier Mario Monti, and the anti-establishment movement led by ex-comedian Beppe Grillo.
Polls are banned within two weeks of the elections, but the most recent ones had Bersani holding onto a slender lead over Berlusconi. Grillo was a distant third.
Italy's political system encourages the forming of alliances.
For example, the Democratic Party has teamed with the more left-wing Left Ecology Freedom party. The center-left alliance is dominated by the Democratic Party, led by Bersani.
The 61-year-old Bersani comes across as "bluff and homespun, and that's part of his appeal -- or not, depending on your point of view," said political analyst James Walston, department chair of international relations at the American University of Rome.
He described Bersani, a former communist, as a "revised apparatchik," saying the reform-minded socialist was paradoxically "far more of a free marketeer than even people on the right."
At second place in the polls is the center-right alliance led by Berlusconi's PdL, in coalition with the right-wing, anti-immigration Northern League.
Berlusconi has given conflicting signals as to whether he is running for the premiership, indicating that he would seek the job if his coalition won, but contradicting that on other occasions.
The septuagenarian playboy billionaire nicknamed "Il Cavaliere" has been campaigning as a Milan court weighs his appeal against a tax fraud conviction, for which he was sentenced to four years in jail last year. The verdict will be delivered after the elections; however, under the Italian legal system, he is entitled to a further appeal in a higher court.
Because the case dates to July 2006, the statute of limitations will expire this year, meaning there is a good chance none of the defendants will serve any prison time.
Why are elections taking place now?
Italian parliamentarians are elected for five-year terms, with the current one due to end in April.
But in December, Berlusconi's People of Freedom Party (PdL) withdrew its support from the reformist government led by Mario Monti, saying it was pursuing policies that "were too German-centric."
Monti subsequently resigned, and the parliament was dissolved.