The head of the Defense Ministry's Okinawa bureau gave two "lectures" urging ministry officials and their family members living in Ginowan to vote in an upcoming mayoral election, indirectly suggesting they support a candidate backing the government's contentious plan to relocate the U.S. Futenma base, the ministry revealed Thursday.

Okinawa Defense Bureau chief Ro Manabe has come under fierce attack since the allegations emerged. His accusers say he used two briefings to influence voting for the Feb. 12 election. Ginowan is the host city for U.S. Marine Corps Air Station Futenma, which some have dubbed "the most dangerous base in Japan."

The opposition parties are accusing Manabe of illegal government "interference" in an election and pressing his boss, Defense Minister Naoki Tanaka, to fire him.