Letta insists his alliance can win the election, with a campaign that puts Europe front and centre.
Enrico Letta, leader of the Democratic Party, is Italy's principal centre-left force and the main rival to Giorgia Meloni, whose political movement leads opinion polls ahead of Sunday's snap general election.
Letta, 56, has already served as the country's prime minister.
He headed a coalition that included centre-right forces after a 2013 election failed to yield a clear-cut majority. But he lost the premiership after barely 10 months when an ambitious fellow Democrat, Matteo Renzi, manoeuvred to take the office for himself.
Burned by the ouster, Letta headed to teach in Paris at the prestigious Sciences Po university. With infighting chronically plaguing the Democrats, he returned to Italy to take back the reins of the party in March 2021.
Letta was foiled in his quest to build a solid centre-left electoral alliance to challenge Meloni and her allies in Sunday's election when the populist Five Star Movement, the largest party in the outgoing parliament, helped to collapse Draghi’s government this summer.
The Democrat Party heads up a left-wing coalition that is trailing in polls to the right-wing bloc that consists of Meloni's Brothers of Italy; Matteo Salvini's Northern League; and Silvio Berlusconi's Go Italy.
Letta's party has a broadly moderate, pro-European stance, and is vehemently opposed to Putin and the war in Ukraine. It also openly supports LGBT rights, including same-sex marriage and legislation to combat homophobia.
It especially cautions against the rise of the Brothers of Italy, which it sees as potentially unleashing an authoritarian tide.
Find out more about Letta in the video, above.