TOKYO: A top Japanese minister embroiled in allegations of missing funds survived a no-confidence motion on Tuesday with embattled premier Fumio Kishida saying he wanted his cabinet chief to stay on despite reports he may be axed in an imminent reshuffle.

The motion against Hirokazu Matsuno, a powerful figure who coordinates policy across government on Kishida's behalf, brought by the main opposition party was comprehensively voted down by 278 members to 166.

After the vote, Kishida - who has seen his public ratings slide to new lows over the allegations that some lawmakers in his ruling party received thousands of dollars in unreported funds - said he wanted Matsuno to continue in his job.

Local media had reported Matsuno was among four cabinet ministers that could be replaced as soon as Wednesday.

Matsuno said on Tuesday he would "take appropriate action" regarding the allegations and wanted to continue to fulfil his duties with "a sense of urgency".

The probe by Tokyo prosecutors centres around the LDP's biggest and most powerful Seiwa-kai faction, formerly led by late prime minister Shinzo Abe and often still referred to as the Abe faction, according to media reports.

They are alleged to have hidden hundreds of millions of yen of political funds over five years in a scheme that saw some lawmakers receiving "kickbacks" from ticket sales to party events that were kept off the books.

Matsuno and the other ministers that media reported could be replaced all hail from that faction.

But in another potential blow for Kishida, a report by NHK on Tuesday said prosecutors were also examining whether his former faction - which he headed until last week - has also under-reported fundraising income.

Asked about the report on Tuesday, Kishida said he had instructed staff to look into any discrepancies and take "appropriate action" as needed.

He had previously said he had not heard about any kickbacks within his faction, from which he withdrew last week in an effort to take a more neutral stance on the escalating scandal.

Political analysts say this could further knock public support for Kishida's administration, which polls show has slumped to a record low of around 23% in recent days, the lowest since he came to office in late 2021.

Support for Kishida's ruling Liberal Democratic Party (LDP) has also fallen below 30% for the first time since 2012, when it returned to power after a blip in its near total post-war dominance of Japanese politics, an NHK survey on Tuesday showed.

Kishida does not need to call an election until October 2025 at the latest, and a fractured and weak opposition has historically struggled to make sustained inroads into the LDP's dominance.

The LDP is due to hold leadership elections in September, but analysts say it remains to be seen how long Kishida can hold on to his post.

"Kishida will remain in power for now as there are no obvious other candidates for the next president, but if a strong contender emerges, there may be a move to drop Kishida," said Yu Uchiyama, a professor of political science at the University of Tokyo.