PM Renzi faces heavy defeat in Italy mayoral elections - exit polls

Virginia Raggi, 5-Star Movement candidate for Rome's mayor, casts her vote at the polling station in Rome, Italy June 19, 2016. REUTERS/Remo Casilli

ROME (Reuters) - The anti-establishment 5-Star Movement looked set to easily win the election for the mayor of Rome on Sunday and clinch a surprise victory in Turin, in a major setback for Prime Minister Matteo Renzi.

The result is a breakthrough for 5-Star and is likely to pile pressure on Renzi, who faces a crucial referendum on constitutional reform in October on which he has staked his political career.