By Gavin Jones
ROME (Reuters) - The leader of Italy's anti-establishment 5-Star Movement said on Thursday he saw the possibility of forming a coalition with the far-right League, but he reiterated his refusal to work with its electoral allies.
Italy held an inconclusive election on March 4 and efforts since then to put together a government have gone nowhere. 5-Star remains adamant in its rejection of the League's longstanding partners, including former prime minister Silvio Berlusconi.
However, 5-Star leader Luigi Di Maio hinted at a possible solution after talks with the head of the upper house, who is acting as a mediator between the parties.
Di Maio said that while he wanted to work exclusively with the League, he could not prevent Berlusconi from supporting such an administration inside parliament, and suggested this solution could potentially be the key to an agreement.
However, a senior Forza Italia lawmaker immediately ruled out the party's offering such so-called "external support" of a government comprising just the 5-Star and the League and said there had been no breakthrough in negotiations.
"Absolutely nothing has changed in the center-right's position," lower house deputy Renato Brunetta told Reuters. "Forza Italia will not give external support to a League and 5-Star government."
Forza Italia later issued a statement saying the center-right bloc remained united and attacking Di Maio for his "immaturity" in trying to divide it.
Senate speaker Maria Casellati is due to report to President Sergio Mattarella on Friday, to inform him if she has made any progress in fostering a coalition.
Di Maio, who on Wednesday had given Salvini a deadline of the end of the week to decide whether to abandon Berlusconi, said he was still willing to talk, but he reiterated that he could not discuss ministerial posts with Berlusconi's party.
5-Star, which bases its appeal on a promise to clean up politics, refuses to countenance a deal with the 81-year-old billionaire, who has a conviction for tax fraud and is on trial for bribing witnesses, a charge he denies.
The euro zone's third-largest economy has been under a caretaker government since the election, when 5-Star and the League were the big winners at the expense of mainstream groups. However, no one party or bloc won a clear majority.
Mattarella turned to Casellati after holding two rounds of fruitless consultations with the various parties himself.
If her efforts also fail, attention will turn to the center-left Democratic Party (PD), which has governed for the last five years and lost badly in last month's ballot.
The PD has said it plans to go into opposition and has rejected appeals from 5-Star to discuss a possible coalition.
However, that determination may be waning. On Tuesday the PD's interim leader, Maurizio Martina, said the party wanted to discuss concrete proposals with whoever got a mandate to form a government.
If all efforts to break the stalemate fail, Mattarella would have to call new elections, probably in the autumn.
(Additional reporting by Crispian Balmer, editing by Larry King)