Japanese Prime Minister Shinzo Abe, left, puts a paper rose on a successful Liberal Democratic Party candidate as party officials Shoichi Nakagawa, center, and Nobuteru Ishihara applaud. They and other party members watched election results Sunday in Tokyo. Projections indicated the LDP would fall far short of the seats it needs to maintain a majority in the upper chamber, allowing the main opposition Democratic Party of Japan to greatly boost its standing.

Tokyo ? Prime Minister Shinzo Abe’s ruling party suffered humiliating losses in parliamentary elections Sunday after a string of political scandals, exit polls showed, but Abe said he did not plan to resign.

The Liberal Democratic Party, which has ruled Japan almost without interruption since 1955, was set to lose its majority in the upper house while the leading opposition party made huge gains, according to exit polls broadcast by Japanese television networks.

Abe said at his party’s headquarters that he intends to stay on despite the disappointing results and accepts responsibility for the defeat.

“We tried our best and felt we made some progress, so the results are extremely disappointing. : I must push ahead with reforms and continue to fulfill my responsibilities as prime minister,” he said. “The responsibility for this utter defeat rests with me.”

The Kyodo news agency reported that the party’s No. 2 official may resign.

“If projections are correct, we are looking at utter defeat,” Liberal Democratic Party secretary-general Hidenao Nakagawa said after polls closed.

According to television network NTV, the polls showed the Liberal Democratic Party and its coalition partner, the New Komei Party, emerging with 104 seats, a 28-seat loss that left it far short of the 122 needed to control the 242-member upper house.

The main opposition Democratic Party of Japan appeared set to emerge with 111 seats, up from 83.

The major defeat could usher in a period of political gridlock. Deep voter dissatisfaction with Abe, fueled by a series of financial and other scandals, appears to have spawned a stunning reversal of fortune for a ruling party that his predecessor, Junichiro Koizumi, led to a landslide in the last elections in 2005.

Opposition leaders immediately jumped on the results as proof the tide had turned against Abe.

“I think there was a lot of hope put on our party,” Takaaki Matsumoto, policy chief for the Democratic Party of Japan, said of the exit polls.

Abe took office less than a year ago as Japan’s youngest prime minister and won points for mending strained diplomatic ties with South Korea and China.

But in the first in a series of scandals, Administrative Reform Minister Genichiro Sata stepped down in December over charges of misusing political funds. In May, Abe’s agriculture minister killed himself amid allegations he too misused public money.

His new agriculture minister also is embroiled in a funds scandal.