Italy Senate to vote on expelling Silvio Berlusconi
Italy's Senate is debating whether to expel ex-PM Silvio Berlusconi over his conviction for tax fraud.
Analysts say his expulsion is expected to be backed by a majority of senators.
Berlusconi told supporters gathered in Rome it was a "day of mourning" for democracy and that the Senate vote was a vendetta by the left.
He vowed that if the vote went against him he would remain in politics to lead his Forza Italia party in a "fight for the good of Italy".
Berlusconi withdrew Forza Italia from the ruling coalition on Tuesday, but the government survived a confidence vote and has passed the budget.
The debate in the Senate has been heated, with two rival senators nearly coming to blows.
Manuela Ripetti of Berlusconi's Forza Italia party shouted: "Your only aim is to eliminate Silvio Berlusconi!"
Berlusconi, who has dominated politics for nearly two decades in Italy, had asked senators to delay the vote on his expulsion because he claims to have new evidence proving he did not commit tax fraud.
However, the vote is expected to go ahead on Wednesday evening. A simple majority of the 321 senators will determine the vote.
Berlusconi's supporters gathered outside his Rome residence, stringing up a banner that read: "It's a coup."
Another placard read: "The Cavaliere (Berlusconi's nickname) is a martyr of freedom".
Berlusconi told his supporters that "no political leader has suffered a persecution such as I have lived through".
He said: "It is a bitter day, a day of mourning."
Berlusconi, 77, told the crowd he could tell it was not just an emotional day for him but for them too.
Appearing to anticipate the outcome of the vote, Berlusconi said his struggle would continue outside parliament.
"We must stay on the field, we must not despair if the leader of the centre-right is not a senator any more. There are leaders of other parties who are not parliamentarians."
He concluded by saying: "Long live Italy, long live Forza Italia, long live liberty!"
One supporter told Reuters: "It is disgusting what they have done. You can just see how the left-wing operate, it is just terrible. How can you kick a person out after 20 years?"
The former PM had threatened to topple the coalition government earlier this year but backed down during a confidence vote when it was clear he would not get the support needed.
Berlusconi was convicted of tax fraud in October 2012 over deals his firm Mediaset made to purchase TV rights to US films. The verdict was upheld in August.
Expulsion from parliament, where he has sat since 1994, may lead to Berlusconi's arrest over other criminal cases, as he would lose his immunity from prosecution.
He will have to serve a one-year sentence for his tax conviction, probably under house arrest or by doing community service because of his age.
He has also been convicted of paying for sex with an underage prostitute and of a breach of confidentiality over a police wiretap. He is appealing against both convictions.
Both Prime Minister Enrico Letta's centre-left Democratic Party (PD) and Beppe Grillo's anti-establishment 5-Star Movement have said they will vote against Berlusconi.
Michele Giarusso, of the 5-Star Movement, said: "Now our country can start to become a normal country where everyone is equal under the law and not where one person thinks they should be above the law."
Mr Letta's government survived a confidence vote on the 2014 budget on Tuesday with the help of a group of dissidents who broke away from Berlusconi's party this month.