Former defense minister Yuriko Koike and veteran journalist Shuntaro Torigoe are leading the race to become Tokyo governor, with former internal affairs minister Hiroya Masuda in third place, according to the latest Kyodo News survey.

But the two-day telephone survey conducted Saturday and Sunday, just days after official campaigning started for the July 31 election, showed around 40 percent of respondents had not decided who to vote for.

Supporters of the ruling Liberal Democratic Party appear split as LDP Lower House member Koike, 64, is running without the backing of the party, which is supporting Masuda, 64, also a former governor of Iwate Prefecture.