The parties that make up Italy’s centre-left alliance voted on Sunday to choose their candidate to run for the job of prime minister.
Around three million people were eligible to take part in the poll.
Italy currently has a technocrat administration which has managed the country’s debt crisis following the fall of Silvio Berlusconi’s government in 2011.
A general election is likely in March to decide a successor to Prime Minister Mario Monti.
The front-runner of five candidates is Pier Luigi Bersani, the main centre-left Democratic Party leader. The career politician is favoured by many party supporters.
But the youthful Mayor of Florence Matteo Renzi is popular among the general population. The 37-year-old’s promised to modernise Italian politics if he’s picked.
The other three candidates include Nichi Vendola, the openly gay governor of the southern Puglia region.
Although voters didn’t need to be party members, they were required to pre-register their support before taking part.
If no candidate wins more than 50 percent support, there will be run off on December 2.
The centre-right is set to hold its own leadership election next month amid confusion over whether Berlusconi will run once again.