Italy's supreme court today began hearing Silvio Berlusconi's last appeal against a jail sentence and ban from public office.

On the first day of the hearing, public prosecutor Antonello Mura rejected most of Berlusconi's arguments that a lower appeal court verdict convicting him of tax fraud was flawed.

However, he requested a reduction of his ban from public office to three years from five on technical legal grounds.

He asked the five supreme court judges to confirm a one-year jail term on Berlusconi.

The case was adjourned tonight until tomorrow, when the court is expected to hear counter-arguments from the four-time prime minister's defence team, with a verdict expected by Thursday.

If the court rejects Berlusconi's appeal it will be the first definitive conviction for the media mogul in dozens of court cases and will mark the end of two decades in which he has dominated politics.

It could also plunge the government - an uneasy coalition of Prime Minister Enrico Letta's centre-left Democratic Party (PD) and Berlusconi's centre-right People of Freedom (PDL) - into crisis and bring renewed uncertainty to the eurozone third's largest economy.

Moderate politicians have urged the court to delay the ruling until September for the sake of political stability.

The 76-year-old media magnate is making his final appeal against the jail sentence and ban from office handed down by lower courts for the fraudulent purchase of broadcasting rights by his Mediaset media empire.

Three other people were also convicted in the case.

If definitively convicted, Berlusconi would not normally go to prison because of his age but would have to do community service or serve his sentence at home.

Berlusconi accuses leftwing magistrates of abusing their powers to try to bring him down in more than two dozen court cases since he stormed to power for the first time in 1994.

The case was fast-tracked to be heard by a special summer session of the supreme court to avoid part of any sentence being annulled by the statute of limitations.

Berlusconi's lawyers have filed 50 objections to the supreme court, which will rule only on legal procedure and whether the lower appeals court properly justified its sentence.

The court has three choices: convict Berlusconi, acquit him or send the case back to the appeals court due to legal errors.

Judicial sources said the prosecutor's request to reduce the ban from public office was because the lower appeal court had made an error in using penal instead of tax law in deciding the punishment.

Even if Berlusconi is found guilty, the ban from holding public office depends on a vote by his peers in the Senate which could take weeks or months.

Berlusconi is also appealing in a lower court against a seven-year jail sentence in June for abuse of office and paying for sex with Moroccan-born nightclub dancer Karima El Mahroug, alias "Ruby the Heartstealer", when she was underage.