Ailing former Prime Minister Noboru Takeshita, who still wields great influence within the ruling Liberal Democratic Party, may retire rather than run in the upcoming Lower House election, sources said Wednesday.

An announcement on his decision may come as early as next month, they said.

Takeshita, 76, the former head of the largest LDP faction, has been in a Tokyo hospital since last April suffering from what is described as lower back pain.

The faction’s current leader is former Prime Minister Keizo Obuchi, who has been comatose since suffering a massive stroke on April 2.

Chief Cabinet Secretary Mikio Aoki, a close aide of Takeshita, declined to comment during a press conference Wednesday afternoon on the possibility of Takeshita’s retirement after his one-year absence from politics.

“There are various reports and speculation about the issue,” Aoki said. “But it is not an issue that I will comment on right here.”

When Takeshita went into the hospital, it was announced at the time that he would be staying a few weeks, but he remains hospitalized and has not been seen in public for more than a year.

Takeshita has maintained a strong influence within the faction and his retirement is likely to have a major impact on its management considering Obuchi’s condition, according to political experts.

Some members are reportedly concerned that with the void in its leadership, the LDP’s largest faction may lose its power and influence.

Some even hinted that Takeshita’s retirement may also damage the faction’s unity, which reportedly lacks a figure who can succeed Obuchi as its head.

Those who do not want Takeshita to retire are reportedly proposing that he stand in the proportional-representation contest instead of running in his Shimane constituency.

The Democratic Party of Japan, the main opposition force, is eager to secure a victory in the constituency, regarding it as a key electoral district, DPJ sources said.

Meanwhile, executives of the Obuchi faction have already begun talks on selecting a new candidate for Takeshita’s constituency, the Shimane No. 2 single-seat constituency, and hope to reach a final decision by early May after factoring in Takeshita’s health and the likelihood of his being re-elected, the sources said.

On Tuesday night, top executive members of the Obuchi faction — including Aoki and Tamisuke Watanuki, former construction minister — discussed whether Takeshita should run in the Lower House election, which must be held before October, the members said.

Takeshita’s office has denied that he is considering retirement.

The Obuchi faction has a complicated power structure, with Watanuki serving as nominal faction leader, while Takeshita is often dubbed the faction’s “owner.”

Obuchi, known as Takeshita’s “favorite disciple,” became head of the faction, which was founded by Takeshita and the late kingmaker Shin Kanemaru. But he stepped down as its leader after being elected LDP president and prime minister, because the LDP adopted a principle barring factions, although they do exist in practice.

Obuchi’s hospitalization early this month apparently prompted Takeshita to start considering retirement, an Obuchi faction source said.

On Wednesday, Aoki, a close aide to Takeshita, denied rumors that he may run in the Shimane No. 2 constituency in the Lower House election as Takeshita’s successor.

“I am not considering it in the least. It is my duty to serve out my term as a House of Councilors member,” Aoki told a press conference.

Aoki was elected from the Shimane constituency to the Upper House.