By Massimiliano Di Giorgio
ROME (Reuters) - Italy's Senate will hold an open vote next month on whether to expel Silvio Berlusconi from parliament because of a tax fraud conviction, after an upper house committee narrowly rejected his bid to make the ballot secret.
The decision has been the subject of intense wrangling, with the billionaire media magnate's political enemies fearing a secret vote might allow him to escape expulsion through backroom dealings.
A special Senate panel voted by 7 to 6 in favour of an open vote, overruling objections from Berlusconi's People of Freedom (PDL) party, which argued that votes on individual senators are traditionally held in secret.
"The panel has voted but it's given birth to a constitutional monster," PDL Senator Anna Maria Bernini told reporters. "This was a decision aimed against one person."
No date has yet been set for the vote, but the Senate agenda is full until November 22, requiring a change to the timetable if the ballot is to be held before then.
Berlusconi is expected to lose his seat in the upper house following his conviction in August for a giant tax fraud at his Mediaset
But the expulsion procedure is proving long and divisive, with the PDL repeatedly trying to delay the vote, which would strip its leader of parliamentary immunity and leave him open to arrest in any of a string of other cases.
Wednesday's decision prompted a flood of anger from Berlusconi's supporters, stoking tensions in Prime Minister Enrico Letta's unwieldy coalition between the PDL and the centre-left Democratic Party (PD).
"Democracy was murdered in the Senate today," said Daniela Santanche, one of the 77-year-old leader's most hardline loyalists. "How can anyone still maintain on the basis of some false idea of stability that this government serves the country?"
The full Senate, where there is a majority in favour of expelling Berlusconi, must vote before the former prime minister can be stripped of his seat under a law passed last year banning convicted criminals from parliament.
However the showdown has been delayed by heated disagreement between Berlusconi's PDL and Letta's PD.
"The decision of the Senate panel should be respected," PD secretary Guglielmo Epifani said in a statement. "People should lower their tone and remember that the law is supposed to be the same for everyone."
Berlusconi, sentenced to four years in prison - commuted to a year under house arrest or in community service - protests his innocence, saying he is the victim of leftwing magistrates.
He also disputes the validity of the law under which he faces expulsion and has threatened to withdraw support for Letta if the Senate votes to throw him out.
As well as the prison sentence, the courts have also barred him from holding public office for two years, which means he will almost certainly be expelled, whatever the result of this Senate vote.
The tensions over the vote have greatly complicated the task facing Letta's government, which must still pass the 2014 budget law before tackling more ambitious reforms to revive Italy's stagnant economy and cut its enormous public debt.
(Writing by James Mackenzie; editing by Barry Moody)