The Yomiuri report comes just hours after U.S. President Donald Trump announced a trade deal with Japan, which will see the Asian economic giant subject to a 15% tariff. Ishiba welcomed the deal, having earlier signaled that he would remain in office at least until a trade agreement with the U.S. was reached.

By Satoshi Sugiyama and Leika Kihara TOKYO (Reuters) -Japanese Prime Minister Shigeru Ishiba plans to announce his resignation by the end of next month, the Mainichi newspaper reported on Wednesday. Ishiba is facing growing opposition from within his Liberal Democratic Party for his vow to stay in power despite the ruling coalition's bruising defeat in Sunday's upper house election.

Anti-establishment parties focused on wages, immigration and an unresponsive political elite struck a chord with working-age people in Japan.

Sanseito, a Japanese populist party that draws inspiration from Donald Trump's politics, is gaining support ahead of Sunday's upper house elections, suggesting a notable shift in the country's traditionally centrist landscape.

Japan's embattled prime minister Shigeru Ishiba, fresh off a crushing defeat in upper house elections over the weekend, will not be in a position of strength to negotiate a favorable trade deal with the U.S., analysts said.

Japan’s Prime Minister Shigeru Ishiba faces a critical test in Sunday’s upper house election. A loss could deepen political instability as his government struggles with rising prices, U.S. tariffs and voter dissatisfaction.

Japan’s voters dealt Prime Minister Ishiba Shigeru of the Liberal Democratic Party (LDP) with yet another devastating blow on Sunday, the second electoral loss since coming into office last fall.

Japanese Prime Minister Shigeru Ishiba’s future is unclear after his coalition appeared to have disastrously lost its upper house majority in elections

Japanese Prime Minister Shigeru Ishiba’s ruling coalition has lost its majority in the upper house of parliament.