TOKYO -- Japan's governing Liberal Democratic Party and junior partner Komeito won a majority of the seats up for grabs in Sunday's upper house election, but the coalition and a conservative ally lost the two-thirds supermajority needed to move ahead with revising the constitution.
The victory gave a tailwind to Prime Minister Shinzo Abe's plans to raise the consumption tax, allowing him to focus on trade talks with the U.S., as well as a widening dispute with South Korea.
Of the 124 seats that were contested, the ruling coalition secured 71, with Abe's LDP winning 57. That is enough to give the coalition a majority in the upper house. It holds 70 seats that were not up for grabs, for a total of 141.
The opposition secured 53 seats, bringing its total to 104.
Parties in favor of revising the constitution -- the LDP, Komeito and the Japan Innovation Party (Nippon Ishin no Kai) -- now hold 157, short of the 164 needed for a two-thirds majority.
The results will force Abe to reach out to conservative members of the opposition to back a constitutional amendment. The prime minister is expected to step up this effort ahead of an extraordinary Diet session to be convened in the fall.
"This election is not about taking two-thirds of the upper house, but about stabilizing Japan's politics," Abe said on a TV program Sunday night. "Constitutional revision is not up to the government, but the Diet. I hope for active discussions on constitutional revision, going forward."
Any proposal to amend the constitution needs a two-thirds vote in the upper and lower houses. It then requires a simple majority in a referendum held 60 to 180 days after approval by parliament. The LDP-Komeito coalition has more than two-thirds of the seats in the lower house.
Several key opposition leaders have already expressed an interest in talks.
"We want to have a full-fledged debate at the Commission on the Constitution based on the LDP's proposal," said Kazuro Matsui, head of the Japan Innovation Party.
"We will take part in the discussion on the constitution," said Democratic Party for the People President Yuichiro Tamaki. "We want to, so we hope [the ruling bloc] creates an environment where we can do that."
But the LDP's coalition partner, Komeito, gave a lukewarm response. "Most citizens already accept the existence of the Self-Defense Forces, and we need further debate on whether we need to write it into the constitution," said Komeito leader Natsuo Yamaguchi. He has previously expressed reservations about amending the constitution.
Abe hopes to amend Article 9 of Japan's pacifist constitution to write the SDF into the charter.
Upper house elections are held every three years, with about half the chamber's 245 seats up for grabs. Members serve six-year terms.
The LDP-Komeito coalition needed to win 53 seats to keep control of the upper house. The LDP would have commanded a majority by itself had it won 67 of the 124 seats.
Voting ended at 8 p.m., and a final count was completed early Monday.
Abe, who doubles as LDP president, had already led his coalition to victory in five national elections since returning as the party's leader in 2012. On Sunday he raised that tally to six.
Tobias Harris, Japan analyst at New York-based risk consultancy Teneo Intelligence, noted the low voter turnout and said, "People find a certain satisfaction in a stable and long-running government."
Abe is on course to become Japan's longest-serving prime minister in November but will have to navigate a number of potential hazards.
In October, Japan's consumption tax is set to rise to 10% from 8%. The planned increase has created a public backlash and fears that it could pull Japan into an economic downturn.
"Everyone said it would be extremely hard to win a majority with the tax hike on the agenda," Abe said after the count began coming in. "But I think we earned people's understanding."
The Abe government will also face the task of moving forward in trade negotiations with the U.S. Both sides have agreed to reach an outcome soon after the election. In regard to U.S. President Donald Trump's protectionism, Abe has been mostly silent despite Japan's total exports recording a seventh straight decline in June, hindered by the impact of the U.S.-China trade war.
Meanwhile, Tokyo's relationship with Seoul continues to sour, with Abe ratcheting up pressure on South Korean President Moon Jae-in by restricting exports of key chipmaking materials to the country.
The prime minister on Sunday night said Tokyo's restrictions on exports of high-tech materials to South Korea are not intended as retaliation against the country over a long-standing wartime labor row. "We have been trying to discuss trade controls with Seoul for about three years, but they have refused to comply," Abe said during a TV interview. "I would like South Korea's sincere cooperation in order to build a relationship of mutual trust between us."
Masahiro Ichikawa, senior strategist at Sumitomo Mitsui DS Asset Management, said, "Although Abe has various issues ahead of him, this election did prove the people's confidence in the ruling coalition. The election outcome is no surprise to the financial markets, but now the attention will likely be on how Abe handles the Japan-U.S. trade negotiations."
Opposition parties sought to boost their electoral chances by joining forces in some districts but nevertheless took a drubbing. Opposition parties now face the task of regrouping so as to better win over voters and compete against the ruling coalition.
Despite the opposition's poor showing overall, the Constitutional Democratic Party doubled its representation in the upper house to 17 seats from nine and strengthened its influence among opposition parties. The Japan Innovation Party picked up three seats, raising its tally to 10.
Meanwhile, the Democratic Party for the People, which split from the CDP, lost two seats, with its total dropping to six. Two political organizations secured a few seats. Reiwa Shinsengumi gained two seats and the Party to Protect the People from NHK took one.
Twenty-eight women won seats, tying the record set in the 2016 election.
Voter turnout was 48.8%, according to the Ministry of Internal Affairs and Communications. The last time the rate fell below 50% was in 1995, when 44.52% of the electorate showed up. Heavy rainfall in western Japan likely dissuaded some people from going to the poll stations on Sunday.