(By Denis Greenan). (ANSA) - Naples, October 23 - A Naples judge on Wednesday sent ex-premier Silvio Berlusconi to trial over allegations he bribed former Senator Sergio De Gregorio to change political sides.
Valter Lavitola, an associate of the ex-premier's, was also indicted for allegedly acting as a go-between.
The trial will begin February 11.
Prosecutors have claimed Lavitola tried to bribe other Senators who have not been identified.
De Gregorio has told investigators he received three million euros from Berlusconi to leave the centre-left government of Romano Prodi in 2008.
Shortly after Berlusconi and Lavitola were indicted, De Gregorio plea-bargained a 20-month sentence over his asserted bribe.
De Gregorio will not go to jail because sentences under two years are automatically suspended.
Prodi's 2006-2008 government fell after losing the support of the Senate, leading to new elections that Berlusconi won.
The ex-premier's indictment added to a series of legal woes for billionaire tycoon Berlusconi, the charismatic centre-right leader who is facing ejection from the Senate and one year of community service for tax fraud at his media group, his first binding conviction in 20 years of judicial battles.
The three-time premier is appealing two convictions by courts of first instance: one for paying for sex with an underage prostitute and abusing his office as premier to try to cover it up; and another for involvement in the publication of an illegal wiretap.
The People of Freedom (PdL) party leader says he has been targeted by politically motivated magistrates since he entered politics in 1994.
Berlusconi's impending ejection from the Senate because of a ban stemming from the fraud conviction has caused a long-running row with the PdL's government partner, the centre-left Democratic Party (PD).
The PdL almost split when pro-government doves forced Berlusconi into an embarrassing U-turn on a confidence vote on the ban.
While the rift was patched up, PdL hawks are insisting the PD should change its stance on approving the ban, which would strip Berlusconi of his parliamentary immunity from arrest.
The two uneasy allies are also squabbling over whether the Senate vote to ratify the ban should be secret - possibly enabling Berlusconi to escape ejection - or not.
The PdL says the existing rules that state the ballot should be secret should apply.
But many members of the PD and the anti-establishment 5-Star Movement (M5S) want the rules changed because they fear a secret ballot would help Berlusconi to persuade lawmakers to break their parties' line and vote for him to keep his seat.
Senate Speaker Pietro Grasso, a PD member and former national anti-Mafia prosecutor, sparked PdL ire by seeming to side with the 'open vote' advocates on Tuesday.
Berlusconi supporters jumped on the De Gregorio indictment to back their leader's claims he is the continuing victim of judicial persecution.
''Nothing new on the Neapolitan front. The strategy of certain judges is clear, as are their ends. Justice reform is a must'', People of Freedom (PdL) House spokesperson Mara Carfagna and former equal opportunities minister commented via Twitter.
''Berlusconi is the victim of the umpteenth episode of clockwork justice. The leader of the largest center-right party finds himself crucified...but Italians know how to distinguish between good and evil, between those who worked on their own behalf and those who worked for the country'', charged Mariastella Gelmini, former education minister and deputy PdL House whip.
''This is the umpteenth violent blow against the millions of voters who, time after time, have freely elected the most important political figure of the past two decades'', thundered the deputy Senate PdL whip Giuseppe Esposito.
Berlusconi's lawyers said they were astonished at the indictment.
''The decision to indict...appears truly extraordinary. Just months ago the same prosecutor's office said corruption had not taken place'', defense attorneys Michele Cerabona and Niccolò Ghedini said.
''De Gregorio...wanted to return to the centre right and by his own admission, all votes cast during the legislature were related to his personal beliefs and not to sums of money, whether promised or received'', the lawyers went on.
''As Lavitola has explained, the cash was given to sort out the accounting situation at (his) L'Avanti newspaper'', they added.
''The trial cannot but shed further light on this situation, and the court will have to recognize the charges are unfounded''.
No PDL MPs came to the defence of Lavitola, a wheeler-dealer who received a two-year, eight-month sentence in March for trying to blackmail Berlusconi in exchange for hushing up payments to escorts at alleged sex parties at the ex-premier's Rome palazzo.
Berlusconi has always denied paying for sex and says he believes the young women were not prostitutes.
Lavitola is also reported to have had a key role in procuring a false document from a Caribbean island to keep ex-House speaker Gianfranco Fini, once a key Berlusconi friend-turned-foe, embroiled in an alleged scandal over a house in Monte Carlo.