Former LDP policy chief Sanae Takaichi, who came in first in the first round of voting in last September's party leadership election but lost to Ishiba in the subsequent runoff, is said to have a strong desire to become the country's first female prime minister.
Before the LDP suffered a historic defeat in this month's House of Councillors election, Takaichi said in her home turf in Nara Prefecture, western Japan, on July 18, "I've made up my mind."
On Wednesday, after the election, Takaichi held talks with about 10 lawmakers close to her, including Upper House member Hiroshi Yamada, at a residential facility for House of Representatives lawmakers in Tokyo.
She also met with former Prime Minister and current LDP supreme adviser Taro Aso, who heads the party's only remaining faction.
Still, Takaichi is distancing herself from the growing calls within the LDP for Ishiba's resignation, apparently hoping to avoid criticism in a possible party leadership election.
She claimed that she and Aso only discussed the Taiwan situation, while an aide to her insisted that she was not present at Wednesday's meeting.
In contrast, former LDP Secretary-General Toshimitsu Motegi is actively seeking to replace Ishiba. He met with Aso on Monday and had dinner on Thursday with several younger lawmakers who belonged to the now-defunct Motegi faction in the LDP.
During the dinner meeting, Motegi declared his intention to become a mainstream force within the LDP.
The former Motegi faction is playing a key role in collecting signatures to hold a general meeting of LDP lawmakers in both Diet chambers to question Ishiba's responsibility for the election defeat.
The party's local chapter in Tochigi Prefecture, headed by Motegi, has submitted a request for Ishiba's resignation.
Nevertheless, some in the party are critical of Motegi's moves, with a former cabinet member saying, "He's doing too much."
Meanwhile, agricultural minister Shinjiro Koizumi has refrained from taking visible action, as he is a member of the Ishiba cabinet.
However, Koizumi was urged by a veteran party member to prepare to assume a "heavy responsibility," and responded that he would like to receive advice, according to informed sources.
On Friday, Koizumi told reporters that he has a "stronger sense of alarm than last year," when he ran in the previous LDP leadership race, as the world is "moving at a tremendous speed and intensity."
Among other possible candidates to succeed Ishiba is Chief Cabinet Secretary Yoshimasa Hayashi, who also joined the party leadership race.
On Monday, Hayashi had dinner with former senior members of a faction that had been led by former Prime Minister Fumio Kishida, including former party policy chief Itsunori Onodera.
On Tuesday, Hayashi visited Kishida at his office for the first time since the launch of the Ishiba cabinet, according to informed sources.
[Copyright The Jiji Press, Ltd.]