TOKYO (Kyodo) -- Japan's opposition parties were in a confident mood Sunday as general election night results showed their numbers in the ascendance and the ruling coalition struggling to maintain its majority in the House of Representatives.

Yoshihiko Noda, the head of the main opposition Constitutional Democratic Party of Japan, hailed the electorate's "good response" as they gave his party its best lower house election result in its seven-year history.

In a television program, Noda also said the continuation of a government headed by the ruling Liberal Democratic Party and its junior coalition partner, the Komeito party, would be "unacceptable."

The LDP has seen its public support erode since the money scandal emerged in late 2023, in which some ruling party members had underreported income from fundraising events.

Noda, a former prime minister who served the country for around a year until 2012 under the now-defunct Democratic Party of Japan, took the reins of the CDPJ in September. His leadership targeted moderate voters with a platform urging political reform.

He said voters had delivered "harsh criticism" over the scandal to the LDP, turning to his party "as they looked to see who would be best to deliver political reform."

On potential cooperation with other opposition parties, Noda said he would be willing to speak with them "so long as they can agree to promote fundamental political reforms."

Among the night's big winners was also the Democratic Party for the People, which projections suggest could significantly boost its seat number from its previous seven.

The party, which campaigned primarily on economic policies to raise incomes for workers, is widely seen as a potential third partner in the LDP-Komeito coalition.

Its leader Yuichiro Tamaki, however, ruled out allying with an LDP and Komeito coalition, telling a television program he would be willing to engage in "policy-by-policy" cooperation.

"On manifesto pledges, we're willing to work with any party, be they government or opposition," he said.

Nobuyuki Baba, head of the Japan Innovation Party, was also quick to rule out entering into a coalition with the LDP and Komeito, saying in a press conference he is "absolutely not considering it" while expressing skepticism on allying with the CDPJ due to policy differences.

The night was a bruising one for his party, which is likely to lose seats.

But Baba professed to being unconcerned about the result, saying he is "proud we were able to do our part to break the coalition majority."