A governor who has been blocking the restart of the world's biggest nuclear power plant in his prefecture has resigned, but it remains to be seen whether the move will create an opening for the nation's pro-nuclear forces.

Niigata Gov. Ryuichi Yoneyama, who campaigned on his opposition to restarting Tokyo Electric Power Co. Holding Inc.'s Kashiwazaki-Kariwa reactors, said Wednesday he would resign over allegations he paid women for sex.

The governor was one of a few high-profile opponents to nuclear power, which the public has viewed with skepticism since the 2011 Fukushima disaster. He was also the biggest roadblock for Tepco's effort to run reactors in his prefecture, two of which have been given the all-clear by regulators. Although the country has imposed stronger safety regulations since 2011, only five of its 39 operable reactors are online.