YOKOHAMA (Kyodo) -- Opposition-backed Takeharu Yamanaka won the Yokohama mayoral election on Sunday, defeating a ruling Liberal Democratic Party candidate in a blow to Prime Minister Yoshihide Suga, according to Kyodo News projections.
The loss by Hachiro Okonogi, a former chairman of the National Public Safety Commission, comes as Suga suffers from falling public support amid dissatisfaction with the government's COVID-19 response.
With a record-high eight candidates contesting the election, Yamanaka, a former professor at Yokohama City University, needs to have received more than 25 percent of ballots to avoid a second ballot, a threshold he is expected to clear.
The result has implications for Suga's hopes of remaining in power as he faces competition to remain LDP leader and a general election in the coming months.
Japan is experiencing its largest wave of COVID-19 yet and dissatisfaction with the prime minister's handling of the pandemic is only growing, with a recent nationwide survey by Kyodo showing support for his Cabinet at a record-low 31.8 percent.
The second-most populous city in the country after Tokyo, Yokohama, the capital of Kanagawa Prefecture, is home to the constituency of Suga's seat in the House of Representatives.
Yamanaka, a 48-year-old data scientist with no prior experience in public office whose work includes analyzing vaccine efficacy on coronavirus variants, ran with the support of the main opposition Constitutional Democratic Party of Japan as well as the Japanese Communist Party and the Social Democratic Party.
He has criticized the government for ignoring calls from infectious disease experts to take stronger measures to curb the spread of COVID-19.
Besides serving as a gauge for Suga's popularity, the Yokohama election served as a referendum of sorts on the city's bid to host a casino after Japan legalized their operation as part of so-called integrated resorts in 2018.
Incumbent Mayor Fumiko Hayashi, 75, who has held the job since 2009 but failed to secure a fourth term, had looked to push ahead with the plan as a way of creating jobs and boosting the city's economy.
Yamanaka is opposed to building the casino, arguing the designated oceanfront property would be better used to build hotels, concert halls and other facilities.
"We will issue a formal statement soon making it clear that Yokohama will not make a hosting bid," he said Sunday night.
Okonogi, who quit the National Public Safety Commission and the lower house to run in the election, was also endorsed by Cabinet members including vaccine czar Taro Kono and Environment Minister Shinjiro Koizumi as well as members of the LDP's junior coalition partner Komeito.
But the 56-year-old only managed to secure votes from 42.7 percent of LDP supporters, according to Kyodo News exit polls, a sign of growing dissatisfaction with Suga among his base. A solid chunk, 19.7 percent, went with Hayashi, who had been backed by some of the party's members in the city assembly.
Among unaffiliated voters, Yamanaka picked up 39.5 percent of ballots, Okonogi 11.1 percent and Hayashi 9.6 percent.
The other candidates included former Kanagawa Gov. Shigefumi Matsuzawa and former Nagano Gov. Yasuo Tanaka.
The city had 3,140,067 eligible voters as of Aug. 7, the day before campaigning officially began. Voter turnout in the previous mayoral election in 2017 was 37.21 percent.