Internal rivals and a resurgent nationalist right are jeopardising Prime Minister Shigeru Ishiba’s already precarious position.

The small rightwing populist party led by firebrand Sohei Kamiya won 14 seats in Sunday’s Upper House election.

The opposition party Sanseito made a strong showing in the July 20 House of Councillors election in both constituency and proportional representation races, greatly boosting its strength from the single seat it secured for the first time in the chamber in the previous 2022 election via proportional representation.

Kamiya’s Sanseito gains ground with anti-globalism and immigration concerns, shaking up politics dominated by Ishiba’s LDP.

The success of Japanese right-wing party Sanseito in Sunday’s upper house election has the potential to unnerve global investors, who have been among the strongest supporters of the nation’s equity markets.

In a significant political shift, Prime Minister Ishiba's coalition lost its majority in Japan's upper house, marking the first such loss for the LDP since 1955. The far-right Sanseito party gained traction with anti-immigrant rhetoric,

Koeda Yoshiyuki, a 51-year-old supporter, called Sanseito “the only party that can truly tackle the big problems Japan faces today”. Sanseito relied on social media, especially YouTube, to reach voters disheartened with politics-as-usual.

Populist ideals are gaining traction in Japan, spurred by right-wing politicians running rampant elsewhere railing against "elitism", "globalism" and immigration.This includes "stricter rules and limits" on immigration and foreign capital,