ROME — Former premier Silvio Berlusconi, who announced this week he wouldn't run in spring elections, says he now feels compelled to stay in politics to reform Italy's justice system after being convicted of tax fraud. Berlusconi's comments came a day after a Milan court sentenced him to four years in prison and barred him from public office for five years. The sentence isn't definitive until all appeals are exhausted, and Berlusconi's lawyers vowed to appeal. Berlusconi denounced the judges as politicized, as he has done in his many legal wrangling with Italian magistrates. He told his private Mediaset television Saturday that he felt “obliged to stay in the game to reform the justice system so that what happened to me doesn't happen to others.” The 76-year-old three-time premier had announced Wednesday that he would not run in the next election due in the spring but did not say he was withdrawing completely from political life. “I will not be presenting my candidacy but I will remain at the side of younger people who can play and score goals,” he said. Two days later he was sentenced to four years in prison for tax fraud, a term reduced to one year thanks to an amnesty. Berlusconi's reaction was defiant. “This is an incredible and intolerable political sentence. This is no doubt a political verdict, as political as all trials fabricated against me,” he said. Italian newspapers splashed the news of Berlusconi's jail sentence across their front pages Saturday, heralding the end of an era dominated by the man one anti-Berlusconi paper called a “natural-born delinquent”. “The mirages and alibis are finished,” said La Stampa. “An entire generation of Italians born after 1975 will for the first time vote in elections next spring that are not a pro- or anti-Berlusconi referendum.” Berlusconi's sentencing put an emphatic punctuation mark on the end of his domination of the Italian political scene. “And so ends a Titanic affair, born in television and finished in court, with a clear, very tough and above all insulting punishment,” wrote the editor of the center-left daily La Repubblica, Ezio Mauro, saying the case highlighted Berlusconi's fall from grace. Left-leaning daily Il Fatto Quotidiano, which had waged war on Berlusconi's government during his three stints as prime minister between 1994 and 2011, said the media tycoon had a “natural capacity for delinquency”. The verdict “is the proof that Italy was governed for nine years by a tax cheat,” said the paper. The disgraced ex-premier looked alternately distraught and defiant in front-page photos. In some shots he wearily pressed a hand to his eye or stared sullenly into space; in others he raised his hands in a protestation of innocence or briskly straightened the lapels of his suit. — Agencies