Rome, April 23 - Pier Luigi Bersani, the outgoing leader of the center left, and fellow members of the troubled Democratic Party (PD) gathered Tuesday in an effort to pick up the pieces of the party following a turbulent round of voting for president in which the PD failed to elect two candidates. Speaking directly to the party for the first time since his resignation Saturday, Bersani said the party had been on the verge of a "very grave crisis" as repeated efforts to elect a PD-backed president late last week faltered, leading to the first-ever re-election of an Italian head of state, Giorgio Napolitano. The centre-left came first in February's vote but did not gain a working majority in the Senate. It ruled out forming a grand coalition with ex-premier Silvio Berlusconi People of Freedom (PdL) party but failed in a bid to reach out to the anti-establishment 5-Star Movement (M5S), which won about a quarter of the vote, leaving the country in a situation of gridlock. Bersani quit as PD chief at the weekend after two candidates he proposed to become head of state were scuppered by rebellions within the party. "I announced my resignation after PD nominees (former Senate Speaker) Franco Marini and (former centre-left premier) Romano Prodi were rejected" by party rebels, Bersani said Tuesday. Bersani also chided "many" of the party's members who he said didn't keep their promises to participate in "formal and collective decisions in a crucial moment". "We were on the edge of an extremely grave crisis without precedent," he said. Later in the day he formalized his resignation, taking a last swipe at those who turned on him and his choices for president in the voting booth. "If there are irresponsible people (in the party) it's my responsibility," Bersani told a party meeting. The internal revolt is widely believed to have been sparked by MPs loyal to Florence Mayor and PD rising star Matteo Renzi, who is now touted as a possible candidate for premier. Despite Renzi's rejection of pursuing the premiership, support was swelling Tuesday, but many of the calls came from the centre right rather than the PD itself, which is without a leader. The PD is now expected to support a so-called 'government of the president', which would also be backed by the PdL, outgoing Premier Mario Monti's Civic Choice party and possibly the Northern League, with a limited mandate to pass some key reforms, including a new electoral law. This administration is set to include institutional figures and possibly PD and PdL politicians, unlike Monti's emergency government of unelected technocrats. While the move would create some level of legislative stability in the short term, pundits say it would also increase the likelihood of an eventual schism within the PD between those who lean center, and those who will not countenance an alliance of any kind with Berlusconi.