Prime Minister Shinzo Abe and Aso, his close ally, are under pressure over the Finance Ministry’s admission that it had made dozens of deletions to 14 documents related to the shady 2016 sale of state land to nationalist school operator Moritomo Gakuen, which has ties to Abe’s wife, Akie, between late February 2017 and April the same year, weeks after the heavily discounted sale was first reported.

The suspicion of a cover-up has rocked the ruling Liberal Democratic Party and could dash Abe’s hopes of winning a third term as party leader in a September vote. Losing the party leadership would ruin Abe’s chances of becoming the country’s longest-serving prime minister. Opposition lawmakers are calling for Aso to step down to take responsibility, and some analysts believe his resignation could be inevitable.

On Tuesday, Aso vowed to look into why documents related to the controversial sale of state-owned land were doctored, as unconvinced opposition parties ratcheted up their criticism against the government.

“My job as finance minister is to identify why it happened and prevent a similar incident in the future,” he told reporters.

Aso was also preparing to skip a Group of 20 finance leaders’ gathering in Buenos Aires next week, officials said Tuesday. When asked whether he may skip the March 19-20 G-20, Aso told reporters that the decision will depend on the “present parliamentary situation.”

“It is important to fully cooperate with the ongoing investigation. To prevent a recurrence, we’ll continue to look into the matter and do the utmost to regain (public) confidence,” Aso said, signaling his intention to ride out the storm.

An LDP lawmaker, speaking on condition of anonymity, said “it will probably be difficult” for Aso to travel overseas “at this time.”

Other government and ruling party officials also said Aso was likely to stay home, and let Masatsugu Asakawa, Japan’s top financial diplomat, attend the G-20 meeting in his place.

The scandal has already caused a stalemate in the Diet, with opposition parties threatening to boycott a debate on next fiscal year’s budget, potentially delaying reforms to boost long-term economic growth.

Their criticism deepened further Tuesday, as the Yomiuri Shimbun daily reported that a Finance Ministry official who committed a suicide earlier this month had left a note, saying the ministry had forced him to alter the documents.

Also Tuesday, LDP Diet affairs head Hiroshi Moriyama denied the opposition parties’ demand to summon to the Diet Akie Abe and National Tax Agency chief Nobuhisa Sagawa, who oversaw the Finance Bureau, after talking with the main opposition Constitutional Democratic Party of Japan’s parliamentary affairs chief Kiyomi Tsujimoto.

The logjam in the Diet could also leave two Bank of Japan deputy governor posts vacant when the incumbents’ terms end on March 19, as the appointments require lawmakers’ approval.

“The firestorm surrounding the cover-up and the land sale will continue to inhibit the administration’s ability to move its agenda through the Diet,” said Tobias Harris, vice president at Teneo Intelligence, a global advisory firm.

With global fears of a potential trade war set to be discussed at the G-20 in Buenos Aires, Aso’s absence would be further evidence of the hindrance the scandal has become for Abe’s government.

On Monday, Aso blamed bureaucrats for the suspected cover-up. But in a rare move, several ruling party heavyweights have openly criticized Abe over the scandal and warned that politicians — not just bureaucrats — must take ultimate responsibility.

A survey by the Sankei Shimbun daily showed 71 percent of respondents said Aso should resign, while support for Abe’s administration slid 6 percentage points from February to 45 percent.

“Aso said he would not … resign to take responsibility for the cover-up. But this approach is unlikely to work for long,” said Harris.

Aso leads a powerful faction within the LDP, and if he is forced to resign and feels betrayed it could erode Abe’s chances of winning another term, analysts say.

While few analysts at this point are predicting the scandal could lead to Abe’s downfall, some say it could impair the prime minister’s focus on the pro-growth, reflationist economic policies known as Abenomics that have become a hallmark of his government. Japan’s economy is enjoying its longest run of growth in 28 years, thanks to robust global demand and capital expenditure.

The scandal has also weighed on markets, though the Nikkei share average managed to rise 0.66 percent on Tuesday. The held firm against the dollar, as the scandal raised doubts about Abe’s ability to pursue economic policies that have kept the yen weak.

“If Aso resigns, that would give Aso’s political faction a freehand, making the LDP leadership race in September extremely fluid. In the worst case, Abe may not make it for the third term,” said Hidenori Suezawa, an analyst at SMBC Nikko Securities. “If Abe goes, Abenomics will go back to square one.”

The protest followed a similar rally staged in front of Abe’s headquarters the previous night, when hundreds were seen chanting “Tell the truth!” and “Abe must quit!.” On Monday, the participants occupied a huge part of the street near the Prime Minister’s Office amid a heavy security presence.

“People who seem incapable of complying with the law are in there,” 61-year-old Shigekazu Ishihara said, pointing his finger in the direction of the Diet.

“Our nation can’t function with people like that at the top. Our democracy is in crisis,” the self-employed man said.

Earlier Monday, the Finance Ministry admitted to making dozens of deletions to 14 documents related to the shady 2016 sale of state land to nationalist school operator Moritomo Gakuen, between late February 2017 and April the same year — weeks after the heavily discounted sale was first reported.

“A person killed himself for it,” 24-year-old university student Takuma Kida asserted, referring to the reported suicide of a Finance Ministry official who handled the Moritomo documents.

“I think it’s getting harder and harder even for those usually apathetic toward politics to stay silent,” Kida said.

“The whole Moritomo scandal began with the idea of politicians using their own influence to ‘privatize’ the administrative process,” said a 40-year-old company employee who asked not to be named.

“For the whole year, they went on without giving a sufficient explanation and now it turns out the Finance Ministry falsified the official documents. … This nation is so over,” she said, voicing hope the rally will help express just how angry the public is.

A 28-year-old company employee who only wished to be identified by his last name, Yamamoto, said it was his first time participating in an anti-government rally.

“I’m just appalled by the sheer difference between what the government says it’s doing and what it’s actually doing,” he said.

“The whole world must be laughing at Japan right now.”

The law on the management of public documents describes administrative documents such as those concerning government decisions as the “people’s common intellectual property” that underpins a healthy democracy. Officials are required to store and manage such documents so that the government’s decision-making processes can be publicly reviewed in the future. The people’s right to know and thus keep the government in check would be undermined if these documents were destroyed or altered at the will of the bureaucracy or the administration in power.

The revelation that the Finance Ministry altered documents related to the 2016 sale of a government-owned tract of land to an Osaka-based school operator, Moritomo Gakuen, when it submitted them to the Diet last year represents a serious breach of public trust in the system. Prime Minister Shinzo Abe has acknowledged that the situation could threaten public trust in the entire government administration. He offered an apology to the public, saying he is keenly aware of his responsibility as head of the government. He needs to follow through on his pledge to get to the bottom of the problem to expose why such an act — which many had said was unthinkable — had taken place, and build a mechanism to make sure such acts would never again take place.

The documents in question relate to the Finance Ministry contract to sell a 8,870-sq.-meter plot of state-owned land in Osaka Prefecture to the school operator at a steep discount for construction of a new elementary school. Since the plot was sold in June 2016 for a mere ¥134 million, a discount of as much as ¥800 million from its appraisal value, favoritism was suspected in the unusual discount. But when the issue was taken up in the Diet early last year, officials insisted that the deal was legitimate — saying the discount had been made to cover the cost of disposing of underground waste found on the site — and denied any political influence or prior negotiations with the school operator over the price.

Then on Monday, the Finance Ministry admitted that parts of the official documents on the land sale to Moritomo Gakuen had been altered between February and April last year before they were disclosed to the Diet in May. Dozens of deletions were made to a total of 14 documents and included references to the prime minister’s wife, Akie Abe, who at that time was named as “honorary principal” of the school that was to be built on the site, as well as several politicians whose aides had contacted the Finance Ministry at the request of the school operator. Also removed from the original documents were phrases like “the special nature” or “exceptional content” of the transaction with Moritomo Gakuen, as well as a sentence stating that the ministry decided to offer the price based on an appraisal made in response to a proposal from the school operator.

In admitting that the documents submitted to the Diet had been altered — days after a media report broke the story — Finance Minister Taro Aso said the documents were rewritten by some officials in the ministry’s Financial Bureau in order to avert inconsistencies with the explanations made earlier to the Diet by Nobuhisa Sagawa, then head of the bureau, about the discount land deal.