ROME - Italy was awaiting a court decision which could emerge Wednesday on whether a law granting Prime Minister Silvio Berlusconi immunity violates the constitution.

The local media speculated a verdict could be imminent just one day after 15 Constitutional Court judges began studying the immunity covering Italy's four most senior officials -- the president, prime minister and two speakers of parliament.

The state attorney acting for Berlusconi has warned that if the top court in the land overturns the law, introduced by the conservative leader last year, he would be so entangled in legal cases that he would be unable to do his job as premier properly.

His center-right allies have even threatened early elections if what they call concentric attacks on Berlusconi over his private life and business dealings continue, though the premier vowed earlier this week to serve out his full term until 2013.

If the court throws out the law we could go into action, mobilizing the people, said Berlusconi's outspoken ally Umberto Bossi, leader of the anti-immigrant Northern League.

One respected opposition figure, Venice's philosopher-mayor Massimo Cacciari, said the verdict could be catastrophic and create a very delicate situation in our country, with Berlusconi hardly able to go on as if nothing had happened.

The Alfano Law, one of Berlusconi's first acts on winning a third term in power last year, halted all the cases against him, including one where he is accused of bribing British lawyer David Mills to give false testimony to protect his businesses.

Two other cases, one accusing him of tax fraud and false accounting in the purchase of TV rights by his Mediaset group and another alleging he tried to corrupt opposition senators, have also been frozen. Berlusconi denies any wrongdoing.

Prosecutors in those cases appealed to the Constitutional Court, arguing that immunity violates fundamental principles such as the equality of all citizens before the law.

UNITED AROUND BERLUSCONI

We are waiting confidently and calmly, said Justice Minister Angelino Alfano, whose name is on the immunity law.

The ruling comes at a time when the 73-year-old premier's normally high approval ratings have been eroded by a series of sex scandals, including prostitutes attending parties at his home -- one of whom went public with some explicit recordings.

The center-right plans a mass rally in coming weeks to show solidarity with Berlusconi in the face of mounting opposition, which Berlusconi says has been orchestrated by the left-wing press in Italy and by biased Italian magistrates.

One thing is clear: the coalition is united around Berlusconi, said Defense Minister Ignazio La Russa.

The center-left opposition admitted that it had missed an opportunity, while in government from 2006-2008, to pass a law on conflict of interests that would prevent the prime minister from owning major TV stations and newspapers while in office.

The center left bears the unforgivable burden of not passing a law on conflict of interests and this must once again be our battle cry, said opposition leader Dario Franceschini.
A deputy from an anti-corruption party was ejected from parliament Wednesday for shouting out Viva don Silvio de Corleone! It accuses Berlusconi of favoring the mafia with a new amnesty to repatriate money held in foreign tax havens.

(Writing by Stephen Brown)