However, with several members absent, the opposition was not enough to defeat the government side which wanted to block the use of wiretap evidence against Nicola Cosentino, a former junior minister accused of links with organized crime.
Benedetto Della Vedova, deputy head of the Future and Liberty group loyal to Berlusconi's estranged former ally Gianfranco Fini, declared in parliament before the vote that the group would back using the wiretap evidence.
But he said the decision was not a signal that the Fini loyalists would vote against the center-right government in a confidence motion that could potentially push Italy into early elections before they are due in 2013.
The result of the vote adds to the uncertain outlook for the Italian government, which has been hampered for months by the fallout from a split between Berlusconi and Fini, co-founders of the ruling People of Freedom (PDL) party.
Fini, who had chafed for months under Berlusconi's dominance of the party, commands the support of 34 lower house deputies and 10 senators who broke away from the PDL in July, depriving the government of a secure majority of at least 316 deputies.
He says he does not want to trigger early elections and will support the government as long as it sticks to its electoral program but will maintain the right to vote against it on individual issues.
However Wednesday's vote highlights the risk that even if no early elections are called, Italy faces the prospect of a prolonged period of parliamentary guerrilla warfare that could seriously affect the government's agenda.
As a member of parliament, Cosentino, who resigned earlier this year over an influence-peddling scandal, enjoys protection against investigation in some circumstances.
