Despite a strong victory by an opposition party-backed candidate over his friend and longtime ally in Sunday’s Yokohama mayoral election, Prime Minister Yoshihide Suga said Monday he will not be changing his plan to seek re-election as Liberal Democratic Party president, a vote which will take place in late September.

But the result is creating concern within the LDP, with some questioning whether continuing with Suga as party leader and prime minister will hurt the party in an upcoming general election.

Constitutional Democratic Party of Japan-backed Takeharu Yamanaka, 48, won the mayor’s seat by defeating seven other candidates. His main rival was former National Public Safety Commission chair Hachiro Okonogi, 56, who Suga had thrown his support behind.