Candidates in Japan's super-tight parliamentary election made last-ditch appeals to voters on Saturday, with opinion polls suggesting the ruling coalition might fall short of a majority.
Such an outcome would be the worst result for the Liberal Democratic Party (LDP) since 2009 and potentially a knockout blow to Prime Minister Shigeru Ishiba, analysts say.
Ishiba -- a fan of trains, 1970s pop idols and making model ships and planes -- only last month took the helm of the LDP, which has governed Japan for almost all of the past seven decades.
After a tough internal contest, the 67-year-old became premier on October 1. Days later, he called snap elections for October 27, promising a "new Japan".
Ishiba pledged to revitalize depressed rural regions and to address the "quiet emergency" of Japan's falling population by supporting families with policies like flexible working hours.
But he has since rowed back his position on issues including allowing married couples to take separate surnames.
He also named only two women ministers in his cabinet.
A new poll on Friday by the Yomiuri Shimbun daily suggested that the LDP and its coalition partner Komeito might struggle to get the 233 lower house seats needed for a majority.
Ishiba has set this threshold as his objective, and missing it would undermine his position in the LDP and mean finding other coalition partners or leading a minority government.
In many districts LDP candidates are in neck-and-neck battles with those of the Constitutional Democratic Party (CDP) -- the second-biggest in parliament -- led by popular former prime minister Yoshihiko Noda.
Noda's stance "is sort of similar to the LDP's. He is basically a conservative," Masato Kamikubo, a political scientist at Ritsumeikan University, told AFP.
"The CDP or Noda can be an alternative to the LDP. Many voters think so," Kamikubo said.
Further dogging Ishiba is the continuing fallout from a slush fund scandal within the LDP that angered voters and helped sink his predecessor, Fumio Kishida.
Ishiba promised to not actively support LDP politicians caught up in the scandal running in the election, although they are still standing.
According to media reports, the party has also provided 20 million yen each to district offices headed by these figures.
"It is truly frustrating that such reports come out at a time like this," Ishiba said in a campaign speech on Thursday. "Those candidates will not use the money."
"We cannot be defeated by those with biased views," he added.
"Regardless of what the election results are, Ishiba's longevity as prime minister is in question," said Rintaro Nishimura at think-tank The Asia Group.