TOKYO (Kyodo) — The main opposition Constitutional Democratic Party of Japan will choose its new leader in a vote on Monday as it gears up for a possible snap election likely to be called by the winner of the ruling party’s presidential contest later this week.

Among the four CDPJ candidates, former Prime Minister Yoshihiko Noda, 67, who led the country under the now-defunct Democratic Party of Japan from 2011 to 2012, is seen as the frontrunner. He has campaigned on a platform to shift the left-leaning CDPJ toward the center.

The other three candidates are the liberal Yukio Edano, 60, who founded the party in 2017, his successor and incumbent Kenta Izumi, 50, and Harumi Yoshida, 52, a first-term House of Representatives lawmaker and the sole female contender in the race .

The 136 CDPJ Diet members and 98 endorsed election candidates will cast ballots in the afternoon in Tokyo worth a total of 370 points under the party’s rules, with another 370 points awarded to votes by local assembly and rank-and-file members, who have already Cast ballots online or by mail.

The race is expected to go to a runoff between Noda and Edano as the party seeks to present an experienced candidate and offer a familiar alternative to the next leader of the Liberal Democratic Party, who will be selected Friday.

Whoever replaces Prime Minister Fumio Kishida as LDP chief is likely to dissolve the lower house for a general election by the end of the year as the party seeks to put behind it a slush funds scandal revealed late last year.

The LDP, which has been in power for most of the period since 1955, has faced intense scrutiny after some of its factions, including one formerly led by Kishida, failed to report portions of their income from fundraising parties and created slush funds.

The CDPJ candidates pledged to clean up politics as part of their efforts to win power, including negotiated “hereditary politics” in Japan, with the fathers of some candidates in the ruling party’s race also having been legislators.

Recommendations from 20 party legislators are required to run in the CDPJ leadership race. While Noda and Edano were quick to confirm their candidacies, Izumi and Yoshida only registered their participation in the run-up to the deadline.

Izumi has served as leader for around three years since taking over in 2021 from Edano, who was forced to resign following criticism over a crushing defeat to the LDP and its junior coalition partner the Komeito party in the lower house election in the same year.

During his tenure, Izumi is believed to have failed to expand voter support, with the candidate backed it in the Tokyo gubernatorial race in July, former upper house member Renho, finishing in third place behind a relatively unknown, social media-savvy former mayor.

On the policy front, the four candidates have been divided on a range of issues including the consumption tax. Noda and Edano have declined to comment to cutting the rate from the current 10 percent. Izumi and Yoshida have called for reducing the tax on food products .

Noda decided to carry out a politically sensitive 5-percentage-point consumption tax hike in 2012, triggering a loss for the DPJ that year and the return to power of the LDP, then headed by the late Prime Minister Shinzo Abe.

The candidates have found common ground on several matters, however, with all expressing support for allowing married couples to choose separate surnames as well as same-sex marriage.