The judges deliberated for four hours before deciding that the trial would go ahead. The defense also decided they didn't need to hear testimony from the Moroccan woman at the center of the case, Karima el-Mahroug, the last witness.
El-Mahroug had appeared in court on Monday ready to testify after having failed to show on two previous dates, purportedly because she was in Mexico on vacation.
Berlusconi is accused of paying for sex with el-Mahroug, better known as Ruby, when she was 17 and during his notorious "bunga bunga" parties — supposedly racy soirees featuring many young women — and then using his office to cover it up. Both deny sexual contact.
El-Mahroug had been the last witness due to testify, meaning a verdict could come before the Feb. 24-25 elections in which Berlusconi is heading a center-right coalition.
Berlusconi's defense lawyer, Niccolo Ghedini, had filed a motion to suspend the proceeding, citing the demands of the election campaign. The prosecution opposed the request, arguing that Berlusconi is not the formal head of his party nor its official candidate for premier, and that he has infrequently shown up for trail anyway, as is his right.
In their ruling, the judges said Berlusconi's absences for a political campaign were a personal choice and couldn't be compared with having a parliamentary obligation — which has been accepted as a legitimate impediment that can allow a trial to be delayed.
Prosecutors had said they didn't need el-Mahroug's court testimony, explaining they had what they needed from other evidence already submitted. Berlusconi's defense, which had originally called her as a witness, said Monday they didn't need to hear her testify. They offered no explanation for the change in strategy.
El-Mahroug's lawyer, Paola Boccardi, said her client wasn't angry that she didn't have to testify, just "surprised that she wasn't heard."
El-Mahroug looked relaxed, chatting with her lawyer. She wore a dark parka with fur trim, Ugg boots and carried a fashionable Louis Vuitton handbag.
In saying that she needn't testify, the judges thanked el-Mahroug for appearing.