Milan, Italy (CNN) -- A panel of judges Monday sentenced former Italian Prime Minister Silvio Berlusconi to seven years in prison for abusing power and having sex with an underage prostitute.
Judges also barred the flamboyant former prime minister from holding public office.
The high-profile case centered on an exotic dancer nicknamed "Ruby the heart-stealer."
Berlusconi's attorney told reporters he plans to appeal the conviction. He said he was not surprised by the verdict, because the former prime minister had not gotten a fair trial.
"What happened today is very serious," defense attorney Nicolo Ghedini said, arguing that judges had not appropriately considered court proceedings.
Prosecutors had argued that Berlusconi had sex 13 times with underage dancer Karima el Mahroug and abused his position when he intervened in May 2010 to get her released from jail, where she was being held on charges of theft.
Berlusconi, 76, has denied the charges and others against him.
"It is absurd to suggest I have paid for a rapport with a woman. It is something I have never done, not even once in my life. It is something I find degrading to my dignity," he has said.
El Mahroug has said that she never had sex with Berlusconi and that she lied to him about her age, telling him she was 24.
The underage sex trial verdict is the latest in a string of legal troubles the former prime minister has faced.
Last month, an Italian appeals court in Milan upheld a four-year prison sentence for Berlusconi, who was convicted of tax evasion by a lower court last October.
In that sentence, he was barred from public office for five years.
Berlusconi, who served on and off as prime minister between 1994 and 2011, is arguably one of the most colorful and controversial figures in the lively history of Italian politics. For years, he has been entangled in fraud, corruption and sex scandals that have often reached Italian courts.
In a 389-page document presented to a court in 2011, prosecutors alleged Berlusconi paid el Mahroug and scores of other young women for taking part in "bunga bunga parties" at his private residence.
Using what they say are phone interceptions of the young women as evidence, prosecutors said the women performed stripteases and erotic actions in exchange for money and gifts. Berlusconi says the parties were normal dinner gatherings where no one misbehaved.
Berlusconi denied the charges and accused prosecutors of conspiring against him in a left-wing plot. "Communism never changes in Italy. There are still people who use the penal code as a weapon in their ideological battles," he said last year.
Undaunted, Berlusconi has not only launched an appeal, but in December made two significant announcements: his engagement to 27-year-old Francesca Pascale, and then, his political comeback.
In Italy's February elections, the three-time prime minister appealed to Italian voters by denouncing the unpopular austerity policies of technocrat Mario Monti.
For all his critics, Berlusconi won almost 30% of the vote in February and remains an influential figure in Prime Minister Enrico Letta's fragile coalition government.
CNN's Becky Anderson, Peter Wilkinson and Paul Armstrong contributed to this report.