Four lawmakers are in the fight to take the helm of the Constitutional Democratic Party, Japan's largest opposition group.

The candidates are Noda Yoshihiko, a former prime minister; Edano Yukio, a former president of the party; current leader Izumi Kenta; and Yoshida Harumi, a rookie lawmaker.

The four held a news conference on Saturday and made their appeals.

Noda spoke to reporters, saying he feels a strong sense of crisis in the political situation. He will take the lead in working together with other opposition parties to tackle corruption.

Edano thinks Japan is at a major crossroads, saying his party must "present a clear path for political reform and offer a vision that meets the expectations of the people."

Izumi stated that they have not just criticized or opposed and that they have worked constructively to develop policies and must build a new government together.

Yoshida wants to create politics that are free from conventional practices. She will advocate for a positive cycle where combining education and the economy will raise the standard of living for all citizens.

The 17-day campaign is expected to focus on how to lay out their strategies to challenge the ruling coalition. Topics will likely include the main governing Liberal Democratic Party's issue of slush funds and how to reform the politics and boosting cooperation among members of the opposition bloc.

Diet lawmakers, local assembly members and general members of the party are eligible to vote. Counting will take place September 23rd, after 17 days of campaigning.