tokyo fast-growing challenge tokyo governor often float japan first possible female premier shinzo abe rule bloc highlight risk gamble snap poll try replicate historic defeat party abe call oct. 22 election hope improve rat struggle opposition would help liberal democratic party-led coalition keep majority low house hold two-thirds super majority abe bet look increasingly shaky give grow support yuriko koike fledgling party hope launch week opposition democratic party move candidates leave party run ticket general election need hold late 2018. abe decision evoke comparison british prime minister theresa may move call snap election june see conservative party lose overall majority although analysts note koike might become even big threat abe wait abe think risk worth take maybe anticipate koike would say daniel sneider stanford university scholar currently research japan grow momentum koike party also revive memories 1993 political drama coalition lead another reformist governor morihiro hosokawa oust ldp first time since found four decades early clearly historical parallel weigh abe mind abe koike democratic party leader seiji maehara elect low house first time year koike maehara hosokawa japan new party abe ldp new party boom 1990s result political confusion long period economic stagnation abe say campaign speech thursday hosokawa fractious alliance fracture less one year abe also cite 2009-12 rule democratic party whose policy flip-flop infighting many voters recall would bear new party boom confusion hope abe say another key player 1993 ichiro ozawa bolt ldp help engineer hosokawa coalition well democratic party 2009 surge power also play role tiny liberal party may also merge koike party like anti-ldp force 1993 democrats 2009 koike promise shed shackle vest interest slogan appeal voters seek alternative ldp former prime minister junichiro koizumi mentor koike late join ldp also skilfully paint old guard party obstacles reform 2005 election win massive victory succeed however koike may take big gamble run election risk backlash quit governor end opposition leader.koike compare french president emmanuel macron meteoric rise repeatedly say stay governor carefully parse comment fail dampen speculation ms. koike say run ... think run chief cabinet secretary yoshihide suga tell reporters friday one day abe call low house poll would great announce boldly debate policies head add apparent challenge despite koike efforts broaden party base absorb many democratic party candidates field big enough slate take majority 465-member low house could tough candidates must register oct. 10. say friday accept democrats want run ticket liberals probably leave even koike defy ldp run governor last year whose local party trounce july tokyo assembly election decide run party challenge still weaken abe ldp fare badly ldp lose 40 seat look good say columbia university professor emeritus gerry curtis energise challenge tokyo governor expose risk pm abe 's snap poll decision