S hinzo Abe is expected to enter the race for president of Japan’s ruling Liberal Democratic Party as early as Sunday with analysts predicting he will again fend off rivals and retain the position of leader of both the party and the nation.

A victory in September would be quite a resurrection for Abe’s fortunes after he looked both physically tired and politically adrift just a few months ago, as criticism from the opposition and media came in hard and fast over cronyism scandals and an unstable administration.

It has taken all of Abe’s political wiles to turn the political tide, but the latest polls suggest he has successfully distanced himself from the stench of underhand dealings. In the most recent public opinion polls, conducted in late June by the Nikkei business daily, Abe’s support rating rose 10 points from the previous month, giving the prime minister a positive figure for the first time since February.

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All up, 52 per cent of the electorate expressed support for Abe in the poll, with supporters identifying the prime minister’s global presence and government stability as the most important factors.

If Abe is successful in convincing politicians and party members, who will vote on the LDP president, that he is the man for the job, then he will be closing in on the record for the longest-serving Japanese leader since the end of the second world war. Eisaku Sato currently holds that record, serving for 2,797 days from November 9, 1964, to July 7, 1972. Abe returned to the post of prime minister after serving only 365 days from September 2006. He has now served 2,030 days since starting his second term on December 16, 2012.

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“Abe’s poll numbers have rebounded strongly in recent weeks, and the main reason is that his main challengers are quite unpopular among conservatives,” said Yoichi Shimada, a professor at Fukui Prefectural University who has in the past advised Abe on foreign policy.

Abe faces three challengers in his bid for the party presidency: Shigeru Ishiba, the former defence minister, Seiko Noda, the minister for internal affairs and communications, and Shinjiro Koizumi, who has served as vice-minister for reconstruction of areas affected by the March 2011 earthquake and tsunami but is presently without a portfolio.

However, Shimada dismissed the other contenders as either too pacifist, too left-wing or simply too young.

“Ishiba opposed the imposition of sanctions on North Korea, which is hard to understand for many Japanese and makes him appear to be an appeaser,” Shimada said. “Historically, he is also perceived to have sided with China and South Korea on issues of history, which makes him an apologist.

“Noda is even further to the left than Ishiba and there are some in the party who say she should not really be a member of the LDP and that her natural home is with a socialist party,” he added.

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The other main potential candidate, Koizumi, “is too young, too inexperienced and lost the support of many in the party when he sided with left-wing newspapers like the Asahi and the opposition were making a fuss over the Moritomo and Kake situations”.

Though Shimada played down the importance of two domestic issues that dominated headlines in the past year, there is no doubt they left Abe bruised.

The Moritomo scandal erupted last autumn when it was claimed that Abe and his wife, Akie, had expressed support for the extreme conservative philosophies of the Moritomo Gakuen kindergarten in Osaka. The operator of the school was then thrust into the spotlight after purchasing a plot of land near the school for a fraction of its value, apparently with the local government’s nod.

The fallout from that episode was exacerbated when it was claimed Abe had intervened with officials at the Ministry of Education on behalf of a friend to arrange a permit to construct a new veterinarian college in Ehime Prefecture.

Robert Dujarric, a professor of politics and international relations at the Tokyo campus of Temple University, said the scandals were fading from public consciousness and may even evaporate entirely by the time the LDP leadership vote arrives.

“In the old days of Japanese politics, scandals were big and brazen – think about Shin Kanemaru and the gold bullion found in his home. So these two situations do not amount to much in the grand scale of things,” he said.

“And there are a lot of positives for Abe at the moment. The economy is not doing badly, he is standing firm on North Korea – which is popular with the public here – and there is no one in the LDP who really stands out as a challenger to his leadership.

“If you were an LDP politician, why would you dump him when your own position arguably depends on him staying on as prime minister?” Dujarric said. “Is there anyone out there who can definitely do better? In short, no.”

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Dujarric said Abe intends to remain prime minister until at least the conclusion of the Tokyo Olympic Games, in the summer of 2020, with a successfully hosted games potentially serving as a high point for him to go out on.

“But who knows?” he asked. “A week is a long time in politics and another scandal could emerge that is too serious for him to shake off. But it is clear that if the election was held today, Abe would win hands down. And, barring a personal disaster for Abe, I see no reason why that would be any different in the September vote.”