The race to be governor of Tokyo has become a contest over the nation’s nuclear policy.

Anti-nuclear former prime minister Morihiro Hosokawa today (Tuesday) said he’ll compete in next month’s election.

Hosokawa is backed by another anti-nuclear ex-prime minister, Junichiro Koizumi.

Current leader Shinzo Abe wants to restart Japan’s nuclear plants, which are offline in the wake of the Fukushima disaster.

Abe said he welcomes a thorough debate on the issues, including Japan’s energy policy and the upcoming 2020 Tokyo Olympics.

Hosokawa is expected to face questions over the money scandal that drove him from power in the early Nineties.

He’ll face former health minister Yoichi Masuzoe, who has the support of Japan's pro-nuclear governing party.

Other candidates include a hawkish former military chief and a liberal lawyer.

The governorship of the world's largest city opened up when incumbent, Naoki Inose, stepped down over his own money problems.