Japan's opposition Democratic Party for the People has decided to suspend its leader, Tamaki Yuichiro, from his post for three months from Wednesday.

The decision was reached at a meeting of the party's lawmakers in both the Lower and Upper Houses of the Diet on Wednesday.

Media outlets reported on an extramarital affair Tamaki was having, to which Tamaki admitted to last month. The party's ethics committee, consisting of three lawmakers, has since studied whether his acts violated the party's ethical rules.

At the meeting on Wednesday, the party's secretary-general Shimba Kazuya proposed a three month-suspension for Tamaki based on the findings of the ethics committee.

Shimba said what Tamaki did runs counter to political ethics and undermined the party's honor and public trust in it. The meeting unanimously approved the proposal.

Lower House member Furukawa Motohisa will serve as acting party president during Tamaki's suspension.

Tamaki is expected to return as the head of the party after the three-month period on March 4 or later.