Italy PM seeks to avert crisis with parliament vote

By Silvia Aloisi

ROME (Reuters) - Italian Prime Minister Romano Prodi goes before parliament on Tuesday to try to avert a government crisis triggered when an ally withdrew from his coalition, but his chances of success appear slim.

Clemente Mastella, whose small Catholic party Udeur had been crucial in ensuring Prodi's slender majority in the Senate, said on Monday his group would no longer back the centre-left government and favored snap elections.

The defection left Prodi in a corner and prompted opposition calls for him to step down right away.

But the premier chose instead to address lawmakers and coerce his allies into a last-ditch show of support with a confidence vote in both chambers of parliament -- he is due to speak in the lower house at 10 a.m. (0900 GMT).

That strategy may only postpone what looks like an inevitable government crisis.

"Doesn't the prime minister have a duty to immediately go to the Quirinale (presidential palace) to offer his resignation?" asked Paolo Bonaiuti, spokesman for opposition leader Silvio Berlusconi, in a statement.

Allies said Prodi was calm and determined to count his votes before throwing in the towel but Mastella, whose three seats in the Senate have helped keep Prodi afloat so far, appeared in no mood for compromise.

"This majority does not exist anymore, this centre left is finished," Mastella said announcing his surprise decision to pull out of the coalition. "We're for elections."

Mastella stepped down as justice minister last week after he and his wife came under investigation in a corruption probe. At the time, he had said his party would provide "external" support to the government. On Monday he said it would no longer do so.

EARLY ELECTIONS?

The most likely scenarios if Prodi is forced to resign are early elections or the forming of an interim government to revamp election laws blamed for Italy's political instability.

Such a government would need widespread, cross-party support, which is far from guaranteed.

Prodi has had a turbulent ride since coming to power in May 2006, after the closest election in modern Italian history.

Weakened by constant infighting in his Catholic-to-communist coalition, he briefly had to resign last year, but no major ally had previously withdrawn support altogether.

Prodi could still win votes in the upper house -- where until now he had a two-seat majority -- with the support of seven unelected lifetime senators as he has done in the past, though their vote cannot be taken for granted.

And the prospect of a referendum to change the electoral law, opposed by several small parties on both sides of the political divide because it would reduce their influence in future coalitions, might tip the balance in favor of early elections with the present system.

"For us the crisis is already happening, there's no need to fiddle around," said Natale D'Amico, a senator from a small centrist party in Prodi's coalition that has often criticized the government.