(By Denis Greenan). Rome, April 18 - Italy's two biggest political guns, Democratic Party (PD) leader Pier Luigi Bersani and centre-right People of Freedom (PdL) chief Silvio Berlusconi, ordered their troops to fire blanks in the second round of voting for Italian president Thursday after PD candidate Franco Marini unexpectedly came up short in the first ballot. With the second ballot effectively void, the PD, which narrowly won February's general election but failed to get a majority in the Senate, bowed to popular pressure and convened a sort of primary Friday morning to elect a candidate capable of mending a party split and reaching out across the floor. Bersani was optimistic a new consensus candidate could be found to muster the required two-thirds majority preferred for a symbol of national unity - and heal the deep rift that opened up inside the PD over ex-Senate Speaker Marini. Topping the bookies' list at the moment is former centre-left premier Romano Prodi, who defeated Berlusconi twice and gained international credibility during a five-year stint at the helm of the European Commission. Marini, an ex-Christian Democrat (DC) trade union leader and brief head of the once-dominant DC's short-lived successor, was viewed by many, especially the followers of PD rising star, Matteo Renzi, as a symbol of an old guard whose time is up. He was also contested because he was the result of a deal between Bersani and Berlusconi, with the controversial PdL leader getting the final pick from a trio of PD possibles. Yet despite Marini's failure and the open divisions in the PD, Bersani was unfazed. "You will see that we will find a solution," Bersani told reporters. "We will bring together the assembly of grand electors and you will see that the solution will be found". He said the PD would come up with a new candidate when its 'grand electors' convene at 8 a.m. Friday, hopefully in a more united mood than Wednesday night's sometimes unruly get-together that eventually led to Bersani getting his way over Marini. Renzi was reportedly set to meet Bersani ahead of the PD huddle amid calls from many on the centre left to switch support to Constitutional lawyer Stefano Rodota', an ex-Communist who was the inaugural chairman of the first heir to Italy's once-strong Communist Party in 1990. Rodota', also a former head of the national privacy watchdog, is the candidate of comedian Beppe Grillo's anti-establishment 5-Star Movement. A two-thirds majority is required in the first three ballots, after which a simple majority will suffice. The third ballot will be Friday morning, and the fourth Friday afternoon. The mood within the PD was captured by leading 'Renzian' MP Simona Bonafe, who called for a candidate the party can rally around. "I hope (Bersani) finds a figure that will bring together the Democratic Party," she said. The left-leaning La Repubblica daily, seen as close to the PD, said Renzi's supporters "are inclining right now towards (former Turin Mayor Sergio) Chiamparino, but the goal remains Prodi". Besides Prodi, other candidates who could come back into the frame, pundits say, are former centre-left premier Giuliano Amato and another ex-premier, Massimo D'Alema, Italy's first and so far only ex-Communist prime minister. D'Alema is seen as less likely to win the approval of the party's renewed line-up of MPs. Bersani, himself an ex-Communist, may still be looking for a winning name to replace Giorgio Napolitano at the weekend, pundits say. Ex-Communist Napolitano was elected by a simple majority in 2006 but came to be regarded as one of the most successful champions of national unity, crossing swords several times with Berlusconi and increasing the heft of a position which had often been seen as merely ceremonial.