By Silvia Aloisi
ROME (Reuters) - Italian Prime Minister Silvio Berlusconi, fighting for the survival of his government, said on Saturday he would seek a confidence vote in parliament after the 2011 budget has been approved.
In a letter to the speakers of both chambers of parliament, Berlusconi said he would first test the strength of his weakened coalition in the Senate and later in the lower house.
Should he lose either vote, he would have to resign, increasing the chances of an early election.
The budget, whose approval is regarded as crucial to avoid rattling financial markets, goes to the floor of the Chamber of Deputies next week and could get the final green light by the upper chamber as early as the following week.
"The government intends to verify whether the grounds for confidence persist in the Senate, and immediately afterwards in the lower house," Berlusconi said in the letter, according to his office.
The fate of the government has hung in the balance since July when, after months of acrimonious exchanges, Berlusconi expelled lower house speaker Gianfranco Fini from the People of Freedom (PDL) party they co-founded in 2008.
The break-up prompted Fini to set up his own party, depriving Berlusconi of a guaranteed majority in the lower house and virtually paralyzing the executive.
Fini demanded last Sunday that Berlusconi resign so that a new center-right coalition including centrists could be formed.
He is expected to withdraw a minister, a deputy minister and two undersecretaries from the government on Monday, further escalating the standoff with his former ally.
Berlusconi, weakened by a string of sex scandals and with his popularity at a record low of 37 percent, has said he has no intention of resigning and wants to force his political enemies to take responsibility for a government collapse by voting against him in parliament.
He already faces a no-confidence motion by the center-left opposition, which has not been scheduled yet.
Political commentators say that by calling a confidence vote himself, the 74-year-old prime minister is trying to regain the political initiative and avert the possibility of a new executive being formed without him at the helm.
By demanding that the first vote be held in the Senate, where he still has a majority, the 74-year old premier hopes to win a lifeline that may make it more difficult for his rivals to bring him down in the lower house.
Different confidence vote results in the two chambers would also make it harder for President Giorgio Napolitano to seek whether a new government can be formed without going to early elections, which opinion polls say Berlusconi would likely win.
(Editing by Jon Boyle)