Italian Prime Minister Silvio Berlusconi won a confidence vote on Thursday on an unpopular 25 billion euro ($32 billion) austerity package, but faces a growing rebellion within his own party.
The government won the vote in the Senate by 170 votes to 136, broadly reflecting the balance of power in the upper house of parliament, where Berlusconi has a comfortable majority.
"It went through very well," said Economy Minister Giulio Tremonti, the package's main architect.
But the very fact that the government had to call a vote of confidence -- which would have forced it to resign had it lost -- revealed the deep rift within the conservative coalition that triumphed in 2008 elections but is now at risk of imploding.
"They are scared about their own majority and they force these things through with a confidence vote, otherwise they would never pass," opposition leader Dario Franceschini said after the vote.
The austerity budget, which includes pay cuts in the public sector and drastic reductions to regional funding, will now go before the lower house, where the government is also expected to call a confidence vote by the end of this month.
Berlusconi is enduring one of the rockiest times in his two-year premiership.
His approval ratings have been falling, a widening corruption scandal has tainted his government, and a showdown with nominal ally Gianfranco Fini, with whom he has been feuding for months, appears only a matter of time.
The resignation on Wednesday of a junior minister implicated in an influence-peddling probe was widely regarded as a sign of the boiling tension between Berlusconi and Fini, the lower house speaker and co-founder of the ruling People of Freedom party.
Economy Ministry Undersecretary Nicola Cosentino had been under mounting pressure to quit after being placed under investigation for suspected involvement in an illegal conspiracy to influence judges and smear rivals within his own party.
Cosentino, who denies any wrongdoing, said in a statement that he was being persecuted not just by the centre-left opposition but also by a power-hungry Fini.
Cosentino's departure was the third resignation from Berlusconi's conservative government over judicial investigations in two months.
But while few expect Berlusconi to last until the end of his term in 2013, the 73-year-old is still likely to ride out the storm for now because the opposition remains weak and Fini has little interest in provoking a government collapse just yet.
"The consequences of blowing the government up would be uncertain for Fini. Berlusconi would try to force a snap election and would likely win it," said James Walston, political science professor at the American University in Rome.
Against the uncertain political backdrop, the austerity package faces opposition from groups ranging from unions to cash-strapped local governments, which say they will not be able to provide proper health and education services.
The government says the measures are essential to bring Italy's budget deficit down from 5.3 percent of GDP to 2.7 percent by 2012, in line with EU requirements, and to reassure markets which fear a widening debt crisis in southern Europe.
But with only modest growth expected this year and consumers feeling the pinch -- 11 percent of Italian families are poor, according to the national statistics institute -- Berlusconi is under pressure to show he can quickly turn the economy around.