ROME, March 7 (Reuters) - Italy is likely to return to the polls very soon after last week's inconclusive vote, the mayor of Florence, seen as a likely new leader of the centre-left in the next election, said on Thursday.
The centre-left won a majority in the lower house of parliament but failed to gain the Senate majority it would need to govern, leaving Italy facing weeks of uncertainty and the possibility of elections within a few months.
"I'll limit myself to saying that this legislature has all the signs of beating the record for duration in a negative sense," Matteo Renzi told the daily Il Messaggero newspaper.
The 38-year-old Renzi has been widely seen as a likely replacement for veteran Democratic Party (PD) leader Pier Luigi Bersani after the centre-left failed to secure victory despite a commanding opinion poll lead in the weeks before the vote.
Renzi, who lost to Bersani in last year's leadership primary, has repeatedly declared his loyalty but said the party needed to draw lessons from the election, which was overshadowed by the runaway success of the anti-establishment 5-Star Movement founded by comic and blogger Beppe Grillo.
"The model of a solid, old-style party has been profoundly put into question," Renzi told the newspaper.
He said another primary to choose a future election candidate was "inevitable", but he declined to say whether he himself would be a candidate.
Renzi, a moderate who is popular outside the PD but is viewed with suspicion by many leftwing traditionalists, has been careful to avoid any overt challenge to Bersani, but his remarks suggest he will play a leading role in any future election.
Bersani has come under growing pressure after a lacklustre campaign allowed both Grillo and former prime minister Silvio Berlusconi to close the gap with the centre-left in the last month of the campaign.
In a front-page cartoon on the Corriere della Sera daily, the 61-year-old former industry minister was shown dressed in the robes of former Pope Benedict, saying "I've been retired even before being made pope".
Bersani secured party backing on Wednesday for an eight-point policy programme he intends to present in parliament.
He has ruled out an alliance with the scandal-tainted Berlusconi and has called on Grillo, who says he will not support any government not led by the 5-Star Movement, to act with responsibility to ensure that Italy can be governed.
President Giorgio Napolitano will start formal consultations with the parties following the first sitting of the new parliament on March 15.