The quit of Japan's Komeito party from the ruling coalition with the Liberal Democratic Party deals a serious blow to the LDP and its new leader in the upcoming election for prime minister.

Tetsuo Saito, chief representative of Komeito, informed the new LDP President Sanae Takaichi of the decision at a meeting on Friday, according to The Asahi Shimbun.

"For the time being, the LDP-Komeito coalition is a blank slate," Saito was quoted as saying at a news conference after the meeting.

Saito said the LDP failed to provide sufficient answers regarding the scandalous political funding and other issues.

With efforts to tackle politics and money being Komeito's top priorities, the party will dissolve the coalition with the LDP and terminate further election cooperation with the party, he said, adding that its lawmakers will vote for Saito, not Takaichi, as prime minister.

Komeito's exit will bring an end to a partnership that has lasted 26 years. It also came at a time when a vote for selecting a new prime minister is expected later this month in the Lower House of the National Diet, Japan's parliament.

Takaichi, who is in a bid to become Japan's first female prime minister, said she was only unilaterally informed by Saito during the meeting of Komeito's withdrawal from the coalition government, according to Kyodo News.

She said Komeito's withdrawal was "deeply regrettable" considering the two parties' past cooperation, including during their time in opposition under the Democratic Party of Japan administration.

Local media reported that the LDP and the government are considering convening an extraordinary parliament session as early as Oct 20 to elect Japan's next prime minister.

The decision by Komeito to end its alliance with the LDP deals a significant blow to the LDP and is set to have a profound impact on Japan's political future, said Hiroshi Shiratori, a professor of political science at Hosei University in Tokyo.

"This move not only means Komeito will withhold support for Sanae Takaichi in the prime ministerial election but could also bring an end to cooperation between the two parties in both national and local elections," Shiratori said.

Long-expected decision

Shiratori said the decision was long expected, as Saito had warned that the excessive conservatism by the LDP made cooperation difficult, while years of cooperation had left Komeito with mounting losses.

"Far from expanding its influence, the alliance has gradually eroded Komeito's power amid the LDP's political and financial controversies," said Shiratori.

The LDP holds the largest number of seats in parliament's Lower House with 196 seats, but still short of a majority. Komeito holds 24 seats.

The main opposition Constitutional Democratic Party of Japan has 148 seats. The party has suggested it may support Yuichiro Tamaki, leader of the Democratic Party for the People, as a prime minister candidate.

CDP Secretary-General Jun Azumi told reporters that after the ruling coalition split, the possibility of a change in government is emerging, depending on the combination of parties formed for the prime minister election.

Takahide Kiuchi, an economist at Nomura Research Institute, told Reuters that if the opposition parties formed a coalition with Komeito and selected Tamaki as their leader, it would result in a government led by an opposition alliance.