A parliamentary committee set up to investigate a political funds scandal that has rocked Japan's ruling Liberal Democratic Party will convene next week, lawmakers said Wednesday, as the LDP looked to make concessions on who will attend in a bid to secure passage of next fiscal year's budget.

The LDP informed opposition parties that three additional senior members of its largest faction will attend the political ethics council hearing in the House of Representatives, a day after saying just two members would attend.

The three lawmakers are former trade minister Yasutoshi Nishimura, former Chief Cabinet Secretary Hirokazu Matsuno and former LDP Diet affairs chief Tsuyoshi Takagi, all of whom have previously served as secretary general of the biggest faction, formerly headed by the late Prime Minister Shinzo Abe.

The LDP has come under intense scrutiny amid allegations that three factions, headed by Abe, former LDP Secretary General Toshihiro Nikai and Prime Minister Fumio Kishida, respectively, neglected to report portions of their incomes from fundraising parties and created slush funds to distribute to their members.

Former trade minister Yasutoshi Nishimura speaks to reporters in Tokyo on Feb. 21, 2024. (Kyodo)

Nishimura told reporters on Wednesday that he will "honestly answer all" questions.

The Abe faction has decided to disband and members have resigned their party or government posts over the scandal.

On Tuesday, the ruling party had notified the opposition parties of the attendance of two members -- Ryu Shionoya, the de facto leader of the Abe faction, and Ryota Takeda, a senior member of the group led by Nikai.

But four opposition parties agreed not to proceed with deliberations on the draft budget for the next fiscal year starting in April, unless a larger number of LDP lawmakers allegedly involved in the scandal, particularly senior members from the two factions, attend the hearing.

The main opposition Constitutional Democratic Party of Japan, along with other forces, also called for a similar committee to be convened in the House of Councillors.

Hiroshige Seko, former LDP secretary general in the upper house and another prominent member of the Abe faction, said he would join a hearing if one were held in the chamber.

The deliberative council on political ethics is responsible for examining the political and moral conduct of lawmakers who face allegations of wrongdoing.

The council can admonish them, such as by recommending they step down from their roles in the Diet or refrain from attending sessions for a period, though no such measures have ever been taken.

Opposition parties have called for all 51 lower house members of the Abe and Nikai factions alleged to be involved in the scandal, especially five key figures of the Abe faction, including Nishimura, Matsuno and Takagi, to testify at the committee.

Attendance at the committee, however, is not compulsory and those giving testimony cannot be held accountable for perjury. The slush funds scandal was revealed late last year.

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