Mr Berlusconi says the legislation will help speed up Italy's legal process
Prime Minister Silvio Berlusconi has labelled Italy's judiciary a "cancerous growth", hours after a bill was passed freezing one of his own trials.
Mr Berlusconi is facing a corruption case in a Milan court, but the new law would postpone the hearing for a year.
The government is also set to introduce another bill that will give top public figures immunity from prosecution.
Mr Berlusconi has faced corruption charges in the courts for many years but has always protested his innocence.
The prime minister argues he has long been a victim of politically biased judges and prosecutors.
Although Mr Berlusconi was found guilty in one corruption case, the verdict was overturned on appeal and other cases were too old to bring to trial.
The stated aim of the new law is to prioritise trials of violent crime and Mafia cases to avoid the danger of them elapsing, as part of Mr Berlusconi's crime crackdown.
But critics say he is using the law to avoid his new term of office being disrupted by further court appearances.
Speaking to a conference of shopkeepers, Mr Berlusconi crossed his wrists as if in handcuffs.
"Many prosecutors would like to see me like this," he told the crowd.
The gesture was greeted with a mixture of jeers, boos and applause.
He claimed to have spent 174m euros (£135m; $271m) on legal fees in a series of cases linked to his business empire, and said he had been persecuted since entering politics in 1994.
On Friday, Mr Berlusconi's cabinet will present a new bill suspending any trials of the five top public office holders, including the prime minister and the president, during the period in which they serve.
A similar law passed by Mr Berlusconi five years ago was subsequently thrown out by the constitutional court, and proceedings against him were reactivated.
The bill passed by Italy's Senate, the upper house of parliament, will freeze for a year trials concerning alleged offences which carry a sentence of less than 10 years.
Italy's National Magistrates' Association urged the government to abandon this measure, which it said would affect some 100,000 trials and cause chaos in the justice system.
Mr Berlusconi's personal lawyer, a member of parliament who helped draft the new legislation, told reporters that the new measures were perfectly fair.
He pointed out that the accused could ask for their trial to go ahead normally, which he said Mr Berlusconi would do in one pending case.
Nonetheless, Mr Berlusconi is coming under increasing political attack for concentrating on his own legal problems, says the BBC's David Willey in Rome.
Critics say he should be concentrating on national issues such as the future of the almost bankrupt national airline Alitalia and the Naples rubbish crisis.