TOKYO (AFP) - Yuriko Koike emerged Wednesday as a possible contender to be Japan's first female prime minister, with heavyweights in the ailing ruling party urging her to challenge conservative favourite Taro Aso. Koike, 56, a former television anchorwoman who has been a defence minister and environment minister, has stayed coy on whether she will contest a party vote on Sept 22 to replace outgoing Prime Minister Yasuo Fukuda. Fukuda, who has faced months of low poll ratings, announced his resignation Monday, plunging Japan's long dominant ruling Liberal Democratic Party (LDP) into crisis mode. General elections must be held by Sept 2009, but the government is in trouble against an emboldened opposition while the economy, the world's second biggest, is teetering on the verge of recession. "I want to consider what we need in general, rather than my own individual situation," Koike told reporters when asked if she would seek the top job.