Supporters of activist Beppe Grillo attend final rally in Rome, Italy on Feb. 22, 2013. Italians go to the polls Sunday and Monday to select their next prime minister from main national parties. (Xinhua/Xu Nizhi)

Pier Luigi Bersani, the leader of Italian center-left Democratic Party, attends final rally in Rome, Italy on Feb. 22, 2013. Italians go to the polls Sunday and Monday to select their next prime minister from main national parties. (Xinhua/Xu Nizhi)

Pier Luigi Bersani, the leader of Italian center-left Democratic Party, attends final rally in Rome, Italy on Feb. 22, 2013. Italians go to the polls Sunday and Monday to select their next prime minister from main national parties. (Xinhua/Xu Nizhi)

Supporters of activist Beppe Grillo attend final rally in Rome, Italy on Feb. 22, 2013. Italians go to the polls Sunday and Monday to select their next prime minister from main national parties. (Xinhua/Xu Nizhi)

Pier Luigi Bersani, the leader of Italian center-left Democratic Party, attends final rally in Rome, Italy on Feb. 22, 2013. Italians go to the polls Sunday and Monday to select their next prime minister from main national parties. (Xinhua/Xu Nizhi)

Pier Luigi Bersani (C), the leader of Italian center-left Democratic Party, attends final rally in Rome, Italy on Feb. 22, 2013. Italians go to the polls Sunday and Monday to select their next prime minister from main national parties. (Xinhua/Xu Nizhi)