Rome  - Italy's upper house of parliament, the Senate, passed Tuesday a bill which protects the country's top officials from prosecution, including Prime Minister Silvio Berlusconi.

The bill, propounded by Berlusconi's conservative coalition, was approved by 171 votes for to 128 against with six abstentions.

It is now set to become law having won approval in both houses of parliament. The lower house Chamber of Deputies passed it on July 11.

Opposition lawmakers from the centre-left who voted against the bill charge it is a measure solely aimed at solving Berlusconi's legal woes.

The law which also grants immunity to the head of state, the president, could force the suspension of two ongoing corruption trials against media billionaire-turned-politician Berlusconi.

"It is a just reform," said Justice Minister, Angelino Alfano, a member of Berlusconi's People of Freedom party, during the debate ahead of the evening Senate vote.

But Anna Finocchiaro, Senate whip for the centre-left Democratic Party, said Berlusconi had placed "no limits" to the exercise of his power through the measure.

Berlusconi, who comfortably won elections in April, has marked his return to power with a series of proposals to overhaul Italy's legal system.

There is broad agreement across the political spectrum that Italy's judiciary which is often slow and inefficient needs to be reformed.

But Berlusconi and his allies also insist that a group of politically motivated left-wing magistrates and prosecutors must be stopped from waging a vendetta against him.

Berlusconi has accused these magistrates of using the courts in an attempt to force him out of office during his three stints as prime minister, beginning with his first election victory in 1994.

Berlusconi is currently on trial in Milan where he is charged with allegedly bribing British lawyer David Mills to lie under oath. A verdict was due before the end of the year.

In a separate case, the premier is accused of committing tax fraud when purchasing film rights for Mediaset, his television company.

Berlusconi and Mills deny any wrongdoing. (dpa)