Mayoral runoffs in Rome, Milan and other big Italian cities are being watched to see how Premier Matteo Renzi's often bickering Democratic Party fares.

The contenders Sunday in the Italian capital are Renzi-backed Roberto Giachetti and the anti-establishment 5-Star Movement's candidate, Virginia Raggi, who could become Rome's first woman mayor.

Corruption scandals have tainted local politicians from both left-leaning and right-wing forces in Rome.

Sports fans will be watching the vote, since Raggi opposes Italy's bid for the 2024 Olympics.

In Milan, Renzi's candidate is Giuseppe Sala, who successfully managed the recent Expo there. Challenging him is Stefano Parisi, a respected manager backed by the center-right.

Naples, Turin and Bologna also have runoffs.

Renzi heads the Democrats, whose unity has been eroded by some who chafe at his take-charge style.