Key opposition lawmaker Tamaki Yuichiro admitted on November 11 to having an extramarital affair.

The leader of the Democratic Party for the People held a press conference where he said the Flash weekly magazine's online report uncovering his meetings with a former model was "mostly true."

S/ Tamaki Yuichiro, Leader, Democratic Party for the People / What has been reported is mostly true. I sincerely apologize not only to my family but also to the many people nationwide who have placed their expectations on us. I am very sorry.

His remarks came ahead of the start of an extraordinary Diet session to choose the next prime minister of Japan.

DPP secretary general Shimba Kazuya told reporters that he harshly reprimanded Tamaki.

While some party members expressed concern over Tamaki’s leadership, Shimba said all lawmakers belonging to the DPP in the end agreed to keep him as their leader and write his name in the parliamentary vote for prime minister.

The DPP has been seen as pivotal as it quadrupled its seats to 28 in October's House of Representatives election in which the ruling coalition failed to secure a combined majority in the lower house.