Italians vote in referendum on duration of oil concessions

A woman casts her ballot for a referendum on the duration of offshore drilling concessions, in Pavia, Italy, Sunday, April 17, 2016. Italians are voting in a referendum on the duration of offshore drilling concessions in territorial waters, as nine regional governments seek to wrestle some influence over energy policy away from the central government in Rome. (AP Photo/Antonio Calanni) (The Associated Press)

A polling station officer shows a ballot for a referendum on the duration of offshore drilling concessions, in Pavia, Italy, Sunday, April 17, 2016. Italians are voting in a referendum on the duration of offshore drilling concessions in territorial waters, as nine regional governments seek to wrestle some influence over energy policy away from the central government in Rome. (AP Photo/Antonio Calanni) (The Associated Press)

Co-founder of 5-Star Movement Beppe Grillo casts his ballot for a referendum on the duration of offshore drilling concessions, in Rome, Sunday, April 17, 2016. Italians are voting in a referendum on the duration of offshore drilling concessions in territorial waters, as nine regional governments seek to wrestle some influence over energy policy away from the central government in Rome. (Luca Zennaro/ANSA via AP) (The Associated Press)

Italians are voting in a referendum on the duration of offshore drilling concessions in territorial waters, as nine regional governments seek to wrestle some influence over energy policy away from the central government in Rome.

Premier Matteo Renzi says he will abstain from voting Sunday, sending a signal that could kill the vote that requires a quorum of 50 percent plus one to make the balloting valid.

The battle began when Renzi's government in December extended all existing 30-year concessions within 12 kilometers (7.5 miles) of shore until resource exhaustion. That angered regional governments, who were concerned about safety, the environment and pushing for a more renewable energy policy.

The amount of resources at stake is equal to 3 percent of Italy's annual domestic demand for gas and 1 percent of annual demand for oil.