ROME (AFP) - Italy's parliament on Wednesday prepared to expel Silvio Berlusconi over his tax fraud conviction in a momentous move that raises the risk of his arrest but is unlikely to end his tumultuous career.

Thousands of Berlusconi loyalists massed outside the three-time former prime minister's luxury home in Rome to support their leader, as lawmakers from his party took the floor of the Senate one by one to back him.

"We are at a crossroads in the history of our country. Whatever happens today, a 20-year era is over," said Pier Ferdinando Casini from the centrist UDC party.

If the ejection goes ahead as expected in a series of votes starting at 1600 GMT on Wednesday (midnight in Singapore on Thursday), the flamboyant billionaire tycoon will be forced out of parliament for the first time since he was first elected in 1994.

"Your only aim is to eliminate Silvio Berlusconi!" mr Manuela Ripetti of Berlusconi's Forza Italia (Go Italy) party shouted at leftist senators in a heated debate.

One loyalist senator even compared the scandal-tainted Berlusconi to South African anti-apartheid icon Nelson Mandela and two rival senators almost came to blows.

Placards held up at the pro-Berlusconi protest read "The Cavaliere is a martyr of freedom" and "The Cavaliere is not to be discussed, he is to be loved".

Berlusconi has asked fellow senators to delay the vote because he claims to have new evidence warranting a review of his conviction and has accused his critics of engineering "a coup d'etat" against him.

In an open letter to senators, Berlusconi said voting against him "would shame you in front of your children, your voters and all Italians", telling them that the vote was "not about me, but about democracy".

But experts said the expulsion marks another step in Berlusconi's slow-motion demise, and there was a mix of indifference and satisfaction in the streets of Rome.

"We managed to put an end to 20 years of fascism, we can put an end to 20 years of Berlusconism too. I hope then we will become a more grown-up country," said Mr Giulio, a passerby in the trendy Trastevere district.

Several polls however show that the 77-year-old Berlusconi's popularity is undimmed among his core supporters and that a centre-right coalition led by him would win elections - although he will not be allowed to take part in the next election after his expulsion.

The political tensions come at an economically crucial time for Italy, which is struggling to end its longest post-war recession, and just as parliament debates a budget aimed at slashing high debt and deficit levels.

Prime Minister Enrico Letta has called for a "non-chaotic situation in Italy" and said a division within Berlusconi's ranks "will help stability".

A group of dissidents led by Berlusconi's former protege, Deputy Prime Minister Angelino Alfano, broke away from his party this month to form their own group.

Mr Alfano and his supporters have said they will vote against Berlusconi's expulsion but will stay in Mr Letta's left-right coalition even if the ejection goes ahead.

The government will therefore not collapse even though Berlusconi's Forza Italia said on Tuesday it was pulling out of the coalition after just six months of uneasy cohabitation with its leftist rivals, who narrowly won a February general election.

The coalition now has a much narrower Senate majority of around 10 seats and could be vulnerable to sniping from Berlusconi even outside parliament.

"Berlusconi is still extremely powerful, although that power is declining," said Dr James Walston, a professor at the American University in Rome.

"He still has enormous resources, he still has his media, he still has lots of very diehard supporters inside and outside parliament," he said.

Ejection from the Senate would remove Berlusconi's parliamentary immunity, which offers safeguards against arrest, and observers say that he is concerned.

Berlusconi's lawyers dismissed the prospect of his arrest, but the former prime minister told one interviewer on Tuesday that prosecutors in Naples and Milan were "competing to see who gets me first".

Berlusconi is currently appealing other convictions for having sex with an underage prostitute, abusing the powers of the prime minister's office and leaking a confidential police wiretap to damage a political rival.

He also faces trial for bribing a leftist senator to join his party's ranks and could come under investigation for paying off young women who attended his raunchy parties to give favourable testimony.