The ruling Liberal Democratic Party decided Tuesday to exclude rank-and-file members from its leadership election that will effectively select Japan's next prime minister, likely benefiting Chief Cabinet Secretary Yoshihide Suga, who has emerged as the front-runner after securing the backing of a majority of party lawmakers.

Two other contenders, former Foreign Minister Fumio Kishida and former Defense Minister Shigeru Ishiba, held press conferences announcing their candidacies, while Suga is expected to do so Wednesday evening.

The LDP's General Council decided to hold an abridged presidential election, with ballots cast only by Diet members and delegates from the party's local chapters, to prevent Prime Minister Shinzo Abe's midterm resignation from creating a political vacuum amid the coronavirus pandemic.

The move was viewed as a setback for Ishiba, a vocal critic of Abe and the prime minister's sole rival in the previous LDP leadership race in 2018. While popular among the public, Ishiba, 63, lacks broad support among fellow lawmakers.

"It is extremely regrettable that not all party members can vote this time around," Ishiba said, adding he will not give up even though the odds are against him.

(From L) Yoshihide Suga, Fumio Kishida and Shigeru Ishiba. (Kyodo)

After more than 140 lawmakers, including Ishiba, signed a petition calling for a full vote, Shunichi Suzuki, who heads the council, said local chapters should gather the opinions of grassroots members ahead of the election to ensure party members' voices are reflected in the process.

The race to pick Abe's successor is expected to kick off on Sept. 8, with the vote held on Sept. 14. The winner of the election will be named the country's next prime minister in an extraordinary Diet session, possibly on Sept. 16, as the ruling party controls the powerful lower house.

Suga, 71, who has been Abe's right-hand man for nearly eight years and is seen as a continuity candidate, has garnered wide support from factions within the party despite not belonging to one himself.

The government's top spokesman told lawmakers calling for him to stand in the election that he will formally declare his intention to run Wednesday evening.

Meanwhile, LDP policy chief Kishida, 63, said in announcing his candidacy that he wants to be "a leader who can gain the cooperation of the people."

One of the more liberal members of the LDP, Kishida has sometimes been criticized for his reluctance, or inability, to step into the spotlight. He passed on running in the previous party leadership race in 2018 to make way for Abe.

A recent Kyodo News poll showed Ishiba was the most popular choice to be the next prime minister, gaining 34.3 percent of support, followed by Suga at 14.3 percent, Defense Minister Taro Kono at 13.6 percent, Environment Minister Shinjiro Koizumi at 10.1 percent and Kishida at 7.5 percent.

The election increasingly looked to be a three-horse race, as other hopefuls announced that they would not stand this time. Kono, 57, said he had decided not to stand after talking to his camp. He belongs to a faction led by Finance Minister Taro Aso, which has decided to back Suga.

Photo taken Aug. 30, 2020, shows Liberal Democratic Party headquarters in Tokyo. (Kyodo)

Foreign Minister Toshimitsu Motegi, who belongs to another faction that is leaning toward supporting Suga, is also forgoing a run, as are Hakubun Shimomura, Tomomi Inada and Seiko Noda.

Following Abe's sudden announcement on Friday that he will resign for health reasons, LDP lawmakers have been scrambling to decide who to throw their support behind as the country grapples with the coronavirus pandemic and a steep recession.

In addition to the 54-member faction fronted by Aso, the LDP's largest faction of 98 members led by former Secretary General Hiroyuki Hosoda has decided to back Suga, according to lawmakers familiar with the matter.

A 47-member group led by LDP Secretary General Toshihiro Nikai also plans to cast votes for Suga, as does a 54-member faction led by former reconstruction minister Wataru Takeshita, and an 11-member group led by former land minister Nobuteru Ishihara.

Kishida leads a faction with 47 members, while Ishiba's faction has 19 members.

In a full-fledged LDP leadership race, candidates would need to secure a majority of the 788 votes up for grabs, with Diet members and rank-and-file members holding 394 votes each.

But this time, a scaled-down version of the election will be held with the 394 Diet member votes and a total of 141 votes cast by three delegates each from the 47 prefectural chapters.

Grassroots members of the LDP were split on being left out of the vote. Masami Hirabuki, a 67-year-old farmer in Kaminoyama, Yamagata Prefecture, said he represents Japan's rapidly aging rural population and wants his voice heard.

Hiroyasu Futagawa, a 46-year-old business owner in Takamatsu, Kagawa Prefecture, said he understands that an abridged election is necessary at this time because of the coronavirus, but the next election in a year's time needs to be a full vote.

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Suga sees support grow as Japan's LDP prepares to choose next leader

Ishiba seen most fit as Abe's successor in Kyodo News poll