Japan's biggest opposition party will seek to support a unified candidate with other groups in a bid to block Sanae Takaichi's election as prime minister, media reported after the ruling coalition collapsed.

Junior partner Komeito quit its 26-year alliance with the ruling Liberal Democratic Party (LDP) on Friday, putting in peril Takaichi's bid to become the country's first woman premier.

Conservative Takaichi was elected as the new LDP president a week ago but needs the approval of parliament to secure the top job.

"This is a once-in-a-decade chance for a change of government," said Yoshihiko Noda, head of the main opposition Constitutional Democratic Party of Japan (CDP), the business Nikkei daily reported late Friday.

Komeito's decision to quit the alliance that has governed Japan a

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