Lex: Japan's prime minister

Yukio Hatoyama, Japan’s prime minister, on Wednesday announced he would step down together with ruling Democratic party heavyweight Ichiro Ozawa, bowing to pressure from colleagues fearful of an impending rout in next month's Diet upper house election. Japanese analysts and media immediately dubbed Naoto Kan, the finance minister, the clear frontrunner to succeed Mr Hatoyama as standard bearer for the DPJ's bold attempt to remake Japanese politics by curbing the power of bureaucrats and stressing cabinet-led policymaking. Louise Lucas analyses the market reaction.