Japan's ruling bloc suffered a major defeat on Sunday's parliamentary election, while the oppositions succeeded in grabbing majority in the House of Councillors.

By 5:00 a.m.(2000 GMT) Monday, the opposition parties and independents, led by the Democratic Party of Japan (DPJ), have secured a total of 75 seats on Sunday's election in which 121 seats were up for grabs. They will hold at least 137 seats in the 242-seats upper chamber, vote counting results showed. There is still a seat to be decided as the vote counting continues.

The ruling bloc of the Liberal Democratic Party (LDP) and New Komeito party won 37 and 8 seats respectively by the same time. The coalition will hold 105 seats at the most in the upper house, compared with 133 before the election.

Prime Minister Shinzo Abe, who led the ruling LDP, said late Sunday that he would stay in power and push forward reforms despite the crushing failure. "Our nation building has just begun. I would like to continue to fulfill my responsibility as prime minister," Abe said on TV Asahi.

Shortly after midnight, LDP Secretary General Hidenao Nakagawa tendered his resignation to Abe, to take responsibility for the unfavorable election results, Kyodo News said.

Abe is considering reshuffling the Cabinet and the leadership of the ruling Liberal Democratic Party possibly in late August, Kyodo News quoted his aides as saying early Monday.

The DPJ, winning at least 60 seats in Sunday's election, will be the chamber's largest bloc. It would be the first time that a party other than the LDP has seized the most seats in the chamber since the LDP was established in 1955. The president of the upper house will therefore be elected from the major opposition DPJ.

The Japanese Communist Party, Social Democratic Party, People's New Party and New Party Nippon won 3, 2, 2 and 1 seats respectively. The independents grabbed 7 seats.

Half of the seats in the upper house come up for grabs every three years and a total of 377 candidates are vying for the 121 seats at stake this time round. Voting started at 7:00 a.m. (2200 GMT, Saturday) on Sunday at over 51,000 polling stations in Japan and ended at 8:00 p.m. (1100 GMT) in most stations.

The turnout rate in Sunday's election reached 58.64 percent forthe prefectural constituency section, up 2.07 percentage points from the previous upper house election in July 2004, according to the election management committees of the nation's 47 prefectures.

According to the internal ministry, the absentee ballots cast totaled some 10.8 million, marking a jump of 50.58 percent from the 2004 election.

As the ruling coalition has a commanding majority in the lower house of the parliament, a failure to maintain majority in the upper house would not immediately reverse the political picture. The House of Representatives is more powerful than the upper house in Japan.

However, the crushing defeat would definitely add pressure to Abe, whose support rate has been dropping to below 40 percent due to pension-recording errors, as well as scandals and controversial remarks involving his Cabinet ministers.

A series of troubles have arisen in the 10 months of Abe's administration. In December, Genichiro Sata resigned his post of administrative reform minister over a scandal that his defunct political support group falsified political fund reports.

A month later, health minister Hakuo Yanagisawa called women "birth-giving machines" in a speech, drawing wide criticism. In May, the Abe Cabinet was dealt another blow, with the farm minister Toshikatsu Matsuoka committed suicide over a political funds scandal. Following the incident, Defense Minister Fumio Kyuma resigned over a remark that appeared to legitimize the 1945 dropping of an atomic bomb on Nagasaki.

The new farm minister, Norihiko Akagi was again under fire over political fund scandals shortly before the election started.

Moreover, the publicity of pension record-keeping errors in late May was another challenge difficult to overcome. Some 50 million unidentified pension accounts due to record-keeping errors would lead many pensioners to get less benefits than they have paid for in premiums. The blunder further deepened public distrust towards Abe's government.

In 1998, the then premier Ryutaro Hashimoto was forced to resign after suffering a major setback in the election.