ROME (Reuters) - Italian lawmakers failed to pick a president in a second round of voting on Friday, but Prime Minister Matteo Renzi appeared poised to get his candidate, a senior judge, elected on Saturday when the number of votes required will be lower.
Renzi's Democratic Party (PD) and a handful of allies pledged on Thursday to back Sergio Mattarella, 73, a constitutional court judge and a veteran center politician.
Any failure by Renzi, who has been in office less than a year, to get Mattarella in would suggest his authority over his party is wavering, raising the prospect of an early national election.
With newly elected Greek Prime Minister Alexis Tsipras facing tricky talks with German-led European partners on renegotiating Greece's debt, a political crisis in Italy would compound uncertainty in the euro zone.
Two votes on the president have so far failed to back a single candidate.
Italy's 1,009 parliamentarians and regional officials eligible to pick the president began voting for a third time on Friday, but the result is likely to be the same, as a two-thirds majority is still needed. The quorum falls to a simple majority of 505 votes in the fourth round, due on Saturday morning.
Then Renzi should have the numbers to elect Mattarella, but the voting by secret ballot has a history of intrigue and unpredictability. Two years ago, two candidates ostensibly backed by the PD fell short because of anonymous defections from within party ranks.
Adding to tension is center leader Silvio Berlusconi's anger at Renzi for betraying what the media tycoon said was a promise to give him a role in choosing the candidate as part of a pact the two leaders made last year to draft institutional reforms together.
"Renzi took Berlusconi off guard," said Clemente Mastella, a former justice minister politically close to Berlusconi. "It will be hard for the center to recompose itself."
While Berlusconi has so far refused to back Mattarella, Reforms Minister Maria Elena Boschi told reporters she was still hoping to bring him on board.
"I hope we can reconcile with Forza Italia, maybe even during the Saturday vote," she said.
Editing by Crispian Balmer