Japanese Prime Minister Shinzo Abe and Finance Minister Taro Aso attend an upper house Budget Committee session in Tokyo, Japan, March 19, 2018. Japanese Prime Minister Shinzo Abe has been under fire amid a deepening cronyism and document-tampering scandal, which has drastically brought down his cabinet's approval ratings, while people staged protests across Japan calling for the cabinet's resignation.(Xinhua/Ma Ping)

TOKYO, March 20 (Xinhua) -- Japanese Prime Minister Shinzo Abe who is currently embroiled in a cut-price land deal scandal said on Tuesday he hoped to regain the public's rapidly eroding trust.

While vowing to thoroughly investigate the protracted and still-unfolding scandal to definitively explaine why the documents related to the dubious sale were deliberately altered, Abe admitted that a recent plunge in support ratings were of serious concern.

The prime minister's remarks were made Tuesday to Natsuo Yamaguchi, the head of the ruling Liberal Democratic Party's (LDP) coalition partner Komeito party.

They were made as concerns have become rife that the prolonged scandal implicating Abe, his wife Akie, and other senior ministers, could seriously hurt Abe's chances of securing a third, three-year term as LDP President and in turn his chances of becoming Japan's longest-serving prime minister.

While the ongoing cronyism and document-tampering scandal has led to the approval rating for Abe's Cabinet tumbling to 38.7 percent over the weekend, Abe has maintained his innocence, despite public and opposition parties' calls for him to step down.

On Monday, the embattled leader reasserted that he and his wife had no involvement in the cut-price land deal with the involved nationalist school operator Moritomo Gakuen, neither in the more recent revelations of document-tampering related to the shady deal. He has even vowed to step down as prime minister if the facts proved otherwise.

But the scandal has continued to unfold with the admission last week by the Finance Ministry that it knowingly tampered with government documents to distance itself from the drawn-out cronyism scandal involving the sale of state land to Moritomo Gakuen for a fraction of its market value.

Furthermore, a construction company connected to the heavily discounted sale of the state land stated recently that it gave false information on buried waste at the site and that this information was requested by the government.

The company said the falsified information it gave on the buried waste led to the land being sold at far below its appraisal value. It said it gave the false information as the school operator along with the government had demanded it do so.

The removal of the fabricated amount of garbage was subtracted from the land price and the plot sold to Moritomo Gakuen at a monumental discount, with the operator planning to build an elementary school there and for Akie Abe, the prime minister's wife, to serve as its honorary principal.

After the scandal first came to light in February last year, Akie quickly severed her affiliation with the school and its operator.

As Abe continues to profess his innocence and Finance Minister Taro Aso said he will not step down for his ministry's involvement in altering government documents, the opposition bloc is stepping up its offensive and has ensured that former head of the National Tax Agency Nobuhisa Sagawa will appear as a sworn witness in the Diet, Japan's bicameral legislature, next Tuesday.

The state documents in question were altered while Sagawa, who has since resigned, headed the ministry's Financial Bureau.

Agreeing that Sagawa is a "key player" in the scandal, the secretaries general and Diet affairs chiefs of the LDP and Komeito on Tuesday accepted the opposition's insistence that Sagawa gives testimony at both the Upper and Lower houses' Budget Committee sessions on Tuesday.