(By Denis Greenan).

(ANSA) - Rome, March 7 - Italian President Giorgio Napolitano on Thursday pledged to do his utmost until the end of his term in May to guide Italy through the political "fog".

The Italian presidency is usually largely a figurehead role but it takes on major importance at the moment after the nation's inconclusive general election produced a hung parliament.

It is up to Napolitano to decide which political leader to give the job of trying to form a new government and then how to proceed if this is not possible.

He is expected to first turn to centre-left leader Pier Luigi Bersani, whose coalition came first but failed to win a working majority in the Senate because of a huge protest vote for comedian Beppe Grillo's 5-Star Movement (M5S), which became the single biggest party in the House.

"I don't know if I'm a lighthouse (for Italy's political world) or an absolutely normal, human light," said Napolitano.

"Sometimes it's difficult to shine light in the fog and I'm trying to do my best".

Bersani, who has framed an eight-point platform for a "government of change" he hopes might lure enough M5S Senators to secure a confidence vote, on Thursday reiterated that it was time Grillo started facing up to the responsibilities his massive support entails.

Bersani directly challenged Grillo, whose M5S unexpectedly won 104 seats in the House and 58 in the Senate, to step up to the plate for the good of the country.

''We're not negotiating, we're simply facing the country with feasible, realistic proposals. The conditions weren't there to make them happen in the past, and now they are'', Bersani said, alluding to the fact that Grillo strenuously opposes forming a coalition with the PD or ex-premier Silvio Berlusconi's People of Freedom (PdL) party, whose centre-right coalition came second in the election.

Bersani, who has ruled out any attempt to forge a grand coalition with Berlusconi, spoke out while presenting the first anti-corruption point of his eight-point platform. ''Grillo does not want diplomacy or seat-swapping, nor do I. But we must give the country proper answers not veiled ones'', he said.

''I don't run around trying to keep up with everything Grillo says morning noon and night. I don't respond to insults.

He could have channeled the protest a different way, but he chose the parliamentary route. Now he needs to take responsibility before the country".

Grillo did not immediately respond to Bersani's call, instead continuing to rail against the Italian media, which he called part of a corrupt system, and claiming there would have been "violence in the streets" without the safety valve the M5S provided for people to vent their rage.

The Italian media have said that if Bersani's government-formation bid fails, as appears likely, Napolitano might favour a technocrat government to enact essential reforms including changing Italy's widely criticised election law, which many say is designed to prevent a clear win, a contention strengthened by the fact that the PD coalition is not able to govern despite winning the popular vote in both houses.

But a senior centre-left figure came out against a second straight technocrat government - after Mario Monti's administration, now taking care of ordinary business, which hauled Italy back from the brink of a Greece-style meltdown but Stefano Fassina, the PD's economic point man, said it would be "impossible" to have another government like Monti's, which has been in power since Berlusconi was forced out with bond yields at unsustainable levels in November 2011.

Any new technocrat government would necessarily have to get a similar majority to that provided by the left, right and centre to ex-European commissioner Monti.

But, driving home Bersani's message, Fassina said: "We are not willing to enter any agreement with the PdL".

"If the conditions are not there for a government of change with the M5S, then it will be necessary to have new elections.

"Berlusconi's PdL does not have the credibility, above all the moral credibility, to be a partner in a phase of change.

"If you want to try for a government that continues the Monti agenda, which was resoundingly rejected by the voters, I say it's better to have new elections". Bersani's eight-point platform features some of the points of the M5S's manifesto, including cuts to the number of lawmakers, a conflict-of-interest law that would cut the knot tying up Italian politics since media magnate Berlusconi joined the fray in 1994, and the introduction of a universal system of unemployment benefits.

The PD leader had talks Thursday evening with Monti, whose centrist reform platform came in a disappointing fourth in the elections.

The two leaders discussed "the priorities of a national reform plan", sources said, and agreed that now was the time for "more growth and jobs" and some loosening of fiscal restraints while complying with EU-mandated targets.

But with Grillo refusing to talk to the media and likely to continue shadow-boxing, the political stalemate is likely to drag on, observers said. The deadlock could make it difficult for the parliament to elect a new head of state before May, when Napolitano's term ends.

The widely respected head of State, 87, on Thursday again ruled out the hypothesis that a solution could be for him to serve a second time.

All previous Italian presidents have served only one seven-year term. "I will do what I have to do until the last day of my term," he said.

"On the eve of the end of my term I want to stress that its conclusion fully corresponds to the conception of the founding fathers (who drew up Italy's Constitution)".