The main opposition Democratic Party of Japan on Sunday was set for its worst showing in a House of Councillors election, Kyodo News exit polls and projections based on early returns showed.
Sunday's early projections showed that the DPJ was certain to secure less than 20 seats, both in prefectural electoral districts and under the party-list proportional representation system, the fewest number since the current DPJ was formed in 1998. The DPJ's predecessor was formed in 1996.
"We were not able to restore public trust," DPJ leader Banri Kaieda told reporters, acknowledging the defeat of his party which has sought to maintain its standing as the country's No. 1 opposition force since losing power in the general election last December, while the ruling coalition of the Liberal Democratic Party and its junior partner, the New Komeito party, was projected to secure a comfortable majority.
The projected outcome is fewer than the 26 seats the DPJ won in the 2001 upper house election.
"To put it simply, the way our party handled the government (when in power) was poor," Kaieda said. "Public expectations turned to disappointment."
The DPJ took the reins of government after a landslide victory in the election for the more powerful House of Representatives in 2009, ending more than 50 years of almost uninterrupted LDP rule.
Public hopes had been high that the DPJ would offer an alternative to the old-style politics of the LDP, but they gradually fizzled out after the DPJ reneged on key policies.
The expected loss of more than half of the 44 DPJ seats that were being contested in Sunday's election is likely to call into question the leadership of DPJ President Banri Kaieda and Secretary General Goshi Hosono.
Hosono said on a TV program that he was "responsible for the election" outcome, hinting at his resignation, while Kaieda expressed his keenness to stay in his post and do more. He said on a separate TV program that his work is still "half done."
In a telling sign of its dwindling support, the DPJ lost in all 19 single-seat constituencies in which it fielded candidates.
In the crucial Tokyo constituency, DPJ lawmaker Kan Suzuki was certain to lose his seat, making it the first time the DPJ has failed to secure a seat in the constituency.
Two LDP lawmakers, Keizo Takemi and Tamayo Marukawa, meanwhile, were assured of seats in the Tokyo constituency, which would be the first time since 1986 that two LDP candidates have been elected.
In the Osaka constituency, DPJ lawmaker Satoshi Umemura lost.
"It was hard to talk about achievements when the DPJ turned into the opposition party last year," said Umemura, who had won a seat at the top of the poll six years ago.
The DPJ was already struggling after faring poorly in last month's Tokyo metropolitan assembly election, when the LDP clinched a sweeping victory.
The party had sought to lure voters by criticizing Prime Minister Shinzo Abe's economic policies, dubbed "Abenomics," which are aimed at beating chronic deflation.