Italian Prime Minister Enrico Letta has announced he is to resign after his own Democratic Party voted against his leadership, with 39-year-old party leader Matteo Renzi now expected to replace him.
Letta plans to submit his resignation to President Giorgio Napolitano on Friday after less than a year at the head of an uneasy left-right coalition and just as Italy is beginning to emerge from a painful recession.
Members of the centre-left Democratic Party's governing directorate voted 136 in favour and 16 against a motion requesting a change of government submitted by Renzi in a dramatic climax to a weeks-long feud with Letta, the AFP news agency reported.
Renzi called on the Democratic Party to back a new "radical programme" and a government that could last until the end of the legislature in 2018.
Italy cannot live in a situation of uncertainty and instability. We are at a crossroads.
"Italy cannot live in a situation of uncertainty and instability. We are at a crossroads," Renzi told a meeting of the Democratic Party's 140-strong leadership committee.
The party thanked Letta, who only came to power in April, for his "positive work" but called for "a new phase with a new executive".
Ever since being elected to lead the party in December, the ambitious and media-savvy Renzi has accused Letta of dragging his feet on crucial political reforms, and failing to do enough to combat rampant unemployment.
Letta will now hold his final cabinet meeting on Friday, then formally submit his resignation to Napolitano who will have to name someone to replace him, with Renzi virtually certain to be his pick.
A new cabinet could be in place by next week, following a round of formal consultations with political parties hosted by the nominee for premier.
In the space of just a few days, a possibility that Renzi himself and top party leaders had excluded until very recently could take shape and Renzi could become the youngest government leader in the European Union.
Unelected prime minister
If Renzi is named prime minister, he would be Italy's third unelected leader in succession after the technocrat Mario Monti and Letta, who was appointed last April after weeks of fruitless wrangling between rival parties, the Reuters news agency reported.
A sharp-talking politician, whose main experience of government has been as mayor of Florence, Renzi is not a member of parliament and has never stood in a national election.
His catchphrases and informal style appeal particularly to younger voters and he often communicates through social media.
Renzi has always said that he would want to become prime minister only with a clear mandate from voters.
However, he said that until the voting law blamed for the last stalemate has been changed, a new ballot was not possible.
"The idea of elections has a certain attraction but it wouldn't guarantee a certain victory for anyone," he said during the speech.
Having burst onto the political scene promising renewal and a break with the Byzantine traditions of Italian politics, Renzi may now gain power with the same type of backroom manoeuvring that characterised revolving door Christian Democrat governments of the past.
Tensions had been rising in the Democratic Party ever since Renzi won the party leadership in December and several experts had said that a long "cohabitation" between Letta and his party's leader would have been impossible.