ROME, Feb. 21 (Xinhua) -- Italian ruling Democratic Party (PD) suffered a first breach on Tuesday, as one minority group officially split from the party, local media reported.
Members of a left-wing faction led by former PD leader Pier Luigi Bersani announced they would no longer attend the PD meetings on Tuesday and Wednesday, according to Ansa news agency.
The PD's former chief in the lower house Roberto Speranza was among the dissidents, but PD governor of Puglia region, Michele Emiliano, decided to stay and challenge Matteo Renzi for the party leadership.
The three were among the highest-ranking PD officials threatening to leave the center-left party due to political tensions with the majority.
Former prime minister Matteo Renzi resigned as leader of the PD on Sunday, opening the way for a battle for power inside the party, which threatens the stability of the current center-left government.
Dissidents and other critics inside the party, have been accusing Renzi of moving the center-left party too much towards the center of the political spectrum.
In a speech after quitting the leadership on Sunday, Renzi acknowledged the defeat of a constitutional referendum in early December was the major setback from which many of the tensions stemmed.
The rejection of the constitutional reform also led to his resignation as prime minister. Yet, Renzi also claimed the party was not to be "blackmailed" by a minority group, and urged critical colleagues to make no "gift" to anti-establishment opposition Five Star Movement (M5S) by weakening the party.
Indeed, the split might now prove a considerable blow for the PD, which is the largest force in the Italian parliament, but currently followed at close distance by the M5S according to national polls.
The group that left on Tuesday is seen as a force to draw 5-8 percent of the vote in a general election, Ansa reported citing various pollsters.
However, the dissidents said they would keep supporting the current government led by Prime Minister Paolo Gentiloni, a PD's member and Renzi's close ally.
In recent years, the PD has been highly regarded, among European social-democratic forces, as one of the few center-left parties able to stand against nationalist and populist forces across the continent.
In the 2014 European parliament elections, the party led by Renzi reached 41 percent of the votes.
