ROME (Reuters) - Former Italian Prime Minister Enrico Letta announced on Friday he would seek the leadership of the troubled centre-left Democratic Party (PD), seven years after he was ousted from power in a party coup. The PD, one of the largest groups supporting Mario Draghi’s unity government, was thrown into turmoil last week when its leader Nicola Zingaretti quit, saying he was “ashamed” of internal wrangling over key positions. His abrupt walkout has triggered a PD slump in the polls and many party stalwarts have turned to Letta, who has been living in Paris in recent years, asking if he would return to Italy and try to revive the centre-left’s fortunes. In a video posted on Twitter, Letta confirmed widespread speculation that he would stand as a candidate to lead the party at a PD assembly called for Sunday. No other PD politician has yet put themselves forward for the top job, and Letta is widely expected to be nominated. “Frankly I would never have imagined last Monday that today I would be here to announce my candidacy for the leadership of the Democratic Party, a party that I helped to found and which is now going through a deep crisis,” Letta said. “I am doing it out of a love of politics and a passion for democratic values.” Moderate and pro-European, Letta led a coalition in 2013-2014 that combined centre-left and centre-right parties. He was unceremoniously booted out of office by party rival Matteo Renzi, who said Italy needed more ambitious government. Livid at his downfall, Letta moved to France where he became director of the Jacques Delors Institute think tank and dean of the Paris School of International Affairs at Sciences Po. He let his membership of the PD lapse, but started paying his dues again in 2019 after Renzi quit the group to set up his own breakaway party, which registers less than 3% in the polls. Support for the PD fell almost 2 percentage points after Zingaretti resigned, hitting just 16.6% in one survey, making it the fourth largest group in Italy behind the 5-Star Movement, and two rightist parties, the League and the Brothers of Italy.