TOKYO:  Prime Minister Shigeru Ishiba’s ruling coalition has lost its majority in Japan’s upper house, winning only 47 of the 50 seats needed to retain control.

Despite the defeat, Ishiba stated he would not resign, focusing instead on ongoing trade negotiations with the United States.

The election followed public frustration over rising inflation, especially in food prices, and anxiety about US tariffs. The coalition had already lost its lower house majority last year, and this result further weakens its authority.

While the opposition Constitutional Democratic Party secured 22 seats, the far-right Sanseito party made notable gains—winning 14 seats, up from just one. Sanseito, led by Sohei Kamiya, capitalized on nationalist sentiment and conspiracy theories popularized during the pandemic.

Experts say many right-leaning voters see Ishiba as too centrist compared to former PM Shinzo Abe. The shift has cost the LDP support from its conservative base, many of whom now back Sanseito’s “Japanese First” stance and anti-immigration rhetoric.

With previous LDP prime ministers stepping down after similar losses, pressure is mounting on Ishiba. Potential challengers include Sanae Takaichi, Takayuki Kobayashi, and Shinjiro Koizumi. Any leadership change could bring fresh political instability.

Despite the political setback, the yen rose slightly in global markets. The Tokyo Stock Exchange was closed on Monday for a public holiday.

In response to rising anti-foreigner sentiment, Ishiba launched a task force to address alleged crimes by foreign nationals. Critics say the move risks inflaming xenophobia as Japan faces growing immigration and tourism-related tensions.