Japan's most popular politician defects from Shinzo Abe's ruling party

Yuriko Koike will lead Tomin First, a political group she set up.
Yuriko Koike will lead Tomin First, a political group she set up.PHOTO: REUTERS

TOKYO (BLOOMBERG) - Japan's most popular politician is severing ties with Prime Minister Shinzo Abe's ruling party, setting the stage for a potentially damaging local election confrontation after she thrashed his candidate in the race to become Tokyo governor last year.

Yuriko Koike said on Thursday (June 1) that she would leave the Liberal Democratic Party to lead a political group she set up to contest the city's assembly elections in July. 

"I want to stand at the head of Tomin First," she said at a news briefing in Tokyo.

The group - whose name translates as Tokyo Residents First - will be counting on her star power to bolster its chances of beating the LDP in next month's vote. Koike, 64, won a landslide victory to become the city's first female governor last year.

Abe and Koike have taken care to keep any animosity under wraps, as the capital prepares to host the 2020 Olympic Games.

But members of his party have tried to paint her as indecisive, after she insisted on reviewing ballooning Olympics costs and delayed a plan to move Tokyo's iconic fish market to a new site, where pollution levels were found to be higher than expected.

Such criticism has done little to dent her popularity. A national poll by Fuji News Network carried out May 13-14 found support for Koike at almost 71 per cent, while 56 per cent of respondents said they backed Abe.

Still, surveys of voting intentions have shown her nascent group lagging behind the LDP.

Japan's capital boasts a population of 13.7 million and a budget roughly equivalent to that of Sweden's.

In a coup for Koike, Abe's Buddhist-backed coalition partner Komeito has thrown its lot in with the governor in the Tokyo elections, while saying that wouldn't affect its national alliance with the LDP. Koike has vowed to seek a female majority in the assembly.

Chief Cabinet Secretary Yoshihide Suga, an LDP lawmaker, told reporters in Tokyo on Thursday that Koike's decision to leave the party would have no impact on how people vote in the election.