• New Sanseito party has signaled support to Ishiba-led coalition government, which lost general elections last year

ISTANBUL

Japanese Prime Minister Shigeru Ishiba said he is determined to remain in office despite a highly expected blow to his Liberal Democratic Party (LPD) in Sunday's Upper House elections, state media reported.

"We must humbly and sincerely accept the harsh situation," Ishiba told a news conference as the ruling coalition struggles to maintain a majority in the 248-member House of Councillors, state broadcaster NHK reported.

Asked if he intends to stay premier and ruling party leader, he said "That's right," as seen on TV Tokyo.

He added, referring to efforts to beat an Aug. 1 deadline for higher US tariffs: "We are engaged in extremely critical tariff negotiations with the US .... We must never derail these negotiations."

The LDP, he said, is still the largest party in parliament by any measure, and thus has major responsibility to deliver results.

The Sanseito party, which is likely to gain several seats in the elections, may link up with the LDP, "depending on policy coordination," its head Sohei Kamiya said, according to Kyodo News.

The party was launched in 2020 and has focused on a "Japanese First" slogan.

Yoshihiko Noda, leader of the opposition Constitutional Democratic Party of Japan (CDP), denied that his party is in any “grand coalition” with the LDP, the Kyodo news agency reported.

If Ishiba continues as premier, the CPD is reportedly mulling a motion of no confidence against him.

No other opposition party has indicated they will support Ishiba in the Upper House.

Results are expected late Sunday.

Millions of voters headed to nearly 45,000 polling stations nationwide to elect 125 lawmakers for the upper house of parliament in a crucial test for the Ishiba-led ruling coalition, which already lost its grip on the lower house last year.

The ruling coalition, made up of the LDP and its junior partner Komeito, currently holds 75 seats, but to maintain a majority in the upper house, it needs to win at least 50 seats from the 125 up for grabs.

The last time the LDP lost its majority in the upper house was in 2007.

The upper house has 248 members serving six-year terms, with elections every three years to fill half of the seats. This year, voters elected the usual 124 members, with an additional seat left vacant.

*Aamir Latif contributed from Pakistan