ROME (Reuters) - Members of Italy s anti-establishment 5-Star Movement, which leads most opinion polls before a national election early next year, began voting on Thursday to elect their leader and candidate for prime minister. Barring a colossal surprise the winner will be Luigi Di Maio, the 31-year-old lower house deputy who has been groomed as leader over the last few years by Beppe Grillo, the comedian who founded 5-Star as a protest movement in 2009. The party s supporters are voting online on a dedicated platform linked to Grillo s blog, reflecting 5-Star s credo of internet-based direct democracy.  Voting will end at 7 p.m. (1700 GMT) on Thursday, but the result will not be known until Saturday, when it is announced at 5-Star s annual three-day gathering in the Adriatic coastal town of Rimini. There are eight candidates, but Di Maio s victory is considered a formality. He is one of Italy s most prominent and popular politicians and his seven rivals, mostly local councillors, are virtually unknown even to 5-Star supporters.  The only people seen as having any chance against him decided not to run, opening the party up to accusations of failing to run a proper contest. Roberto Saviano, author of the best-selling novel Gomorra, said on Facebook that he wanted to run for the post  to help 5-Star out of a pathetic situation . Saviano is not a party member and so is not eligible. Probably the only risk for Di Maio would be if voting were distorted by another hacking attack against 5-Star s internet platform. In August an anonymous hacker revealed he had broken into the system to obtain secret data on 5-Star s members and donors.       
Italy's 5-Star Movement votes for leader, Di Maio seen winning