An Italian court hearing Silvio Berlusconi's high court challenge to his tax fraud conviction will wait until Thursday to deliberate.

Chief Justice Antonio Esposito put off the deliberations one more day after Berlusconi's reinforced defense team wrapped up 2.5 hours of arguments Wednesday.

Esposito cited the late hour and the importance of the case.

Berlusconi, a three-time former premier, risks a swift halt to his 20-year political career if the high court confirms the conviction, a four-year jail term and five-year ban on political office.

The controversial billionaire and three others were convicted in October of tax fraud in the purchase of television rights for Berlusconi's Mediaset network.He was sentenced to four years with a five-year ban on public office, which was confirmed on appeal.

This is his final appeal, and if confirmed by Italy's highest court, Berlusconi would lose his Senate seat and be banned from running in elections.

The state prosecutor has recommended lowering the public office ban to three years, which Berlusconi's defence said indicates a "blatant error" in the sentencing.

Defendants rarely attend court hearings, and Berlusconi was not present on Tuesday or Wednesday.

A police patrol was posted in front of his Rome residence and outside the Court of Cassation, where local and international media were gathered.

Public opinion in Italy is split between those who think he's guilty and must be sent to prison, and those who see Berlusconi as a victim of a system that targets rich and powerful men.

"I think they are targeting him, and until they beat him up they won't let him go," said Rome resident Marcello Conte.

But Carlo Romani, walking to work past the courthouse on Wednesday said he hoped Berlusconi would be sent down.

"I hope they will take the right decision, I hope they will sentence him guilty," he said.

Berlusconi's defence is expected to be the last to argue on Wednesday.

The decision, which could have an impact on Italy's fragile, three-month-old coalition government, could come later on Wednesday or on Thursday.

Berlusconi has no official role in the country's cabinet, but remains influential, and holds a seat in the Senate, which he would have to vacate if the court upholds his conviction.