(By Denis Greenan). Rome, April 15 - The anti-establishment 5-Star Movement (M5S) on Monday voted on a shortlist of candidates to replace Giorgio Napolitano as Italian president next month, with no deal in sight between the top parties that emerged from an inconclusive February general election. M5S leader, comedian-turned politician Beppe Grillo, pulled out of the 'primaries' while thanking his supporters for honouring him, while Grillo's guru Gianroberto Casaleggio said the movement shouldn't choose any of the political candidates that had been shortlisted. "We want an impartial figure, not someone from any of the parties, someone who can represent all Italians," Casaleggio said. If movement members heed Casaleggio's call, that would appear to rule out former European commissioner and Radical Party heavyweight Emma Bonino and former centre-left premier Romano Prodi. The Italian media are looking at the poll, whose results will come out Tuesday, for an idea of what a possible consensus candidate could be for the two parties that came out just ahead of Grillo in the general election, Pier Luigi Bersani's centre-left Democratic Party (PD) and ex-premier Silvio Berlusconi's centre-right People of Freedom (PdL) party. "M5S might be able to stake a claim to becoming a king maker," said Italy's top daily, Corriere della Sera. "One thing is sure, the PD and PdL don't look like agreeing on anyone any time soon, and perhaps Grillo's candidate decision could give them a useful nudge," it said. A PD-Pdl deal is not essential for the election because the centre left almost has a majority of the 1007 'grand electors' who will start voting Thursday. Pundits say they could easily attract some centrists to get their candidate elected when it comes down to a simple majority in the fourth ballot, and not the three-thirds required in the first three. But given Italy's widening political and social rifts - dramatically captured by the huge protest vote that gave Grillo the balance of power in a hung parliament - pundits say the country is in deep need of a cross-party figure capable of expressing a large degree of parliamentary and national unity, as Italian presidents traditionally have. Even though M5S House Whip Roberta Lombardi reiterated Monday that "we're only going to vote for our own candidate", pundits think a Grillo candidate who also garners support from the two other main parties would be a godsend at a time of deep division and disenchantment. The people on Grillo's shortlist include Prodi; Bonino; war-zone doctor Gino Strada; Supreme Court Chief Justice Ferdinando Imposimato; respected investigative journalist Milena Gabanelli; institutional lawyers Stefano Rodota' and Gustavo Zagrebelsky; former Palermo prosecutor Gian Carlo Caselli; and Nobel Literature Laureate Dario Fo. Fo, however is just nine months younger than the 87-year-old Napolitano, and has already said he does not want to be head of state. Strada, 64, Imposimato, 77, and Gabanelli, 59, came top of the shortlist, in that order. None of them has connections to a specific party, though both Strada and Gabanelli are left-wing, and would thus seem to fit the bill after Casaleggio's diktat. But according to Corriere della Sera, Bersani is set to propose three names: former premier Giuliano Amato, a respected institutional experts despite the nickname he got as aide to late Socialist premier Bettino Craxi, 'Doctor Subtle'; Prodi; and ex-Senate Speaker Franco Marini. "Bersani is going to ask the PdL to pick from a threesome rather than advancing one take-it-or-leave it candidate," the Milan-based newspaper said. Whoever is elected will have the job of trying to shepherd a new government into existence despite Bersani's continuing resistance to an alliance with Berlusconi, or else call a snap vote, expected in July. According to recent opinion polls, the impasse has boosted the PdL past the PD, with M5S also losing some ground. Some observers had speculated the two old-guard parties might form a 'targeted government' to pass voter-friendly laws and deflate Grillo's support - while Grillo was banking on what he called an 'inciucio' ('stitch-up' or backroom deal) to strengthen anti-establishment sentiment and make M5S the top party next time around. Meanwhile a poll released Monday said more and more Italians are getting tired of Grillo's stonewalling tactics - but supporters of his movement are giving them ever-stronger backing. The survey by SWG market researchers found that about 62% of Italians do not approve of the strategy taken by the M5S MPs. But 76% of those who say they are members of the movement back him to the hilt. The survey also found that 43% of those surveyed approved of the rookie parliamentarians elected under the M5S banner, a much lower approval rating than the 92% approval reported by party members.