Former health minister Francesco Storace was ordered to stand trial on Friday for alleged dirty tricks ahead of Italy's 2005 regional elections.
Rome judge Enrico Imprudente indicted Storace and six of his assistants, saying the trial would start on May 15.
Storace, a top member of the rightist National Alliance (AN), unsuccessfully sought re-election in 2005 as the governor of Lazio, the region surrounding Rome.
He is accused of trying to sabotage the election campaign of hard-right rival Alessandra Mussolini by having her declared guilty of electoral registration malpractice.
The six other defendants are: Storace's ex-spokesman Nicolo' Accame; his former aide Tiziana Perreca; detective Pierpaolo Pasqua; Mirko Maceri, the former technical director of information technology firm Laziomatica; Nicola Santoro, the son of a judge involved in the case; and Vincenzo Piso, a former Rome AN official.
The suspects face a range of charges including breaking electoral laws and conspiring to gain illegal access to a Rome city council database.
Storace, who is now a senator, is accused of "ordering and instigating" the computer break-in.
The former governor, who after his election defeat was appointed health minister by then premier Silvio Berlusconi, said on Friday that he was certain of being acquitted.
"I'm unperturbed and confident in the statistics, because in Italy, 70% of trials end in an acquittal even though it costs the taxpayer," the burly lawmaker said.
Legal experts noted that in the event of a guilty verdict, Storace and the other suspects would in any case benefit from a prisoner pardon recently approved by parliament which covers certain crimes committed prior to May 2006. The controversial amnesty also applies to sentences which have yet to be handed down.
Two key witnesses in the case, former Storace aide Dario Pettinelli and detective Gaspare Gallo, initially faced trial themselves but agreed to collaborate with investigators in order to ease their legal position.
MUSSOLINI PETITION TAMPERED WITH.
Accame and Pasqua are accused of falsifying the signatures on Mussolini's petition to stand in the regional elections.
In order to participate in regional polls, small parties need to collect a certain number of signatures from people who want them to stand. In Lazio the minimum is 3,500.
Mussolini, the granddaughter of Fascist dictator Benito Mussolini, was initially excluded from the race after signatures presented by her small, hard-right Social Alternative party were found to be false.
More than 800 signatures on Mussolini's petition were declared fraudulent. The list included names of the deceased and others whose existence was dubious, such as people who gave their birth date as February 31.
Mussolini was eventually allowed to take part in the election but Rome prosecutors opened an inquiry into the case.
It subsequently emerged that Laziomatica, a company which answered to Storace's regional administration, had hacked into the computer archives of Rome city hall and checked hundreds of names on Mussolini's list of signatures.
Members of Storace's party, which is the second biggest party in the Berlusconi-led opposition, expressed solidarity with the senator on Friday and said he was sure to prove his innocence.
Former communications minister and AN heavyweight Maurizio Gasparri said that "Storace will come out of this with his head held high".
But Mussolini told reporters: "Those who committed this crime must pay for it, not for my sake but for the sake of democracy".
A lawmaker with the Democratic Left, the largest party in the centre-left government headed by Romano Prodi, said that "it's undeniable that the period of Storace's governorship was characterised by serious misconduct and worrying acts".
Storace's five-year record as Lazio governor has also been marred by a major corruption probe involving alleged kickbacks in the health sector, the fraudulent appropriation of European Union funds and the alleged channelling of regional monies into organisations and firms run by relatives and friends of regional politicians.
Storace is not under investigation but his former regional transport councillor, Giulio Gargano, has already been sentenced to more than four years in a preliminary trial and another of his former aides has been arrested.
The main suspect, private health manager Anna Iannuzzi, is on trial accused of obtaining fraudulent reimbursements from the Lazio regional government.
She has testified to prosecutors that she handed over some 25,000 euros a month in kickbacks to the Storace administration.
