The approval rating for Japanese Prime Minister Shinzo Abe's Cabinet has plunged over ten points since May to under 45 percent.
The Nikkei business daily, citing government and ruling party sources, said Mr Abe would rejig his Cabinet in August or September.
Regarding allegations that Abe pressured bureaucrats to approve a new veterinary department at a university run by his close friend, 73.8 percent said they were not convinced by the government's now hollow denials.
Abe has repeatedly denied abusing his authority to benefit his friend. The ministry had earlier said it could not find the documents but reopened the probe under public pressure.
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Nonetheless, Mr Nalvany's social media-savvy supporters have got their own YouTube channel - broadcasting from across the country. It warned that authorities would take all necessary measures to prevent provocations or any action threatening public security.
The Prime Minister has also been hit by another scandal in recent weeks, involving allegations that he granted special favours for the set-up of a new veterinary college at Kake Educational Institution, headed by his friend.
Nearly 85 percent of voters responding to a Kyodo news agency survey said they did not think the government probe had uncovered the truth of the affair and almost 74 percent were not persuaded by the government's insistence that there was nothing wrong with the approval process. Voters were split over last week's enactment by Parliament of a controversial law that will penalise conspiracies to commit terrorism and other serious crimes.
In the nationwide telephone survey on Saturday and Sunday, 67.7 percent of the public was found to disapprove of the unorthodox procedural tactics used by the ruling coalition to ram the contentious conspiracy bill through the Diet.
The ruling coalition of the Liberal Democratic Party and the Komeito party used its majority, so the amendment to the law could clear a vote in an upper house plenary session, after the Abe-led bloc bypassed an upper house committee vote.