Nothing short of force majeure will prevent Yoshihide Suga from becoming Japan’s prime minister when the ruling Liberal Democratic party (LDP) elects a leader to replace Shinzo Abe this week.

As chief cabinet secretary for almost eight years, Suga has acted as the administration’s de facto second-in-command, batting away tricky questions at twice-daily press briefings, advising Abe on policy and reining in Japan’s recalcitrant bureaucracy.

Suga has emerged as the clear favourite to replace Abe, who is resigning on health grounds, since securing the support of key LDP factions. After what observers predict will be a comfortable victory on Monday over his rivals, the party’s policy chief, Fumio Kishida, and Shigeru Ishiba, a former defence minister, Suga is practically assured of being approved as prime minister in the lower house of parliament on Wednesday.

After the controversial decision to exclude from the election just over 1 million rank-and-file LDP members – among whom Ishiba is the more popular candidate – Suga’s installation as prime minister has come to resemble an anointment.

The 71-year-old is widely seen as the Abe continuity candidate, a label he has done little to contradict during his leadership bid. His predecessor’s economic policy – a combination of huge government spending, ultra-easy monetary policy and structural reforms – will remain untouched, he has said.

“The only reason Suga got the premiership is because he vowed to continue Abe’s policies, so for a new prime minister he is unusually constrained by the record and legacy of the previous government,” said Koichi Nakano, a political science professor at Sophia University in Tokyo.

“Having served as Abe’s defender-in chief, Suga cannot disown Abe and push through major policy transformation without incurring strong criticism. His hands are tied.”

On foreign policy, Suga will continue to prioritise Japan’s security ties with the US in the face of an assertive China and nuclear-armed North Korea, although he admitted on Sunday that he lacked the “diplomatic skills” that helped Abe forge a close personal relationship with Donald Trump.

Despite his close political association with Abe, Suga’s background could not be more different. As the son of a foreign minister and grandson of a prime minister, Abe stands out even in a parliament packed with hereditary politicians. Suga, however, is a self-made politician, the eldest son of a strawberry farmer and teacher in Yuzawa, a town in rural Akita prefecture, who despite his lack of political pedigree is now on the cusp of leading the world’s third-biggest economy.

“He was very quiet,” Hiroshi Kawai, a former high school classmate, said of Suga. “He was someone you wouldn’t notice if he was there or not.”

After graduating from high school in Yuzawa – where his name is now emblazoned on T-shirts and tote bags – Suga travelled to Tokyo, where he took a series of part-time jobs, including stints at a cardboard factory and Tsukiji fish market, to pay his way through university.

His career in politics began in 1987, when he reportedly wore out half a dozen pairs of shoes while canvassing, successfully, for a seat on the Yokohama city assembly, where he became known as the “shadow mayor”.

Suga’s status as a relative outsider could serve him well as he attempts to steer Japan out of a prolonged recession worsened by the coronavirus pandemic, according to Tobias Harris, a Japan expert at Teneo Intelligence in Washington and the author of a new book on Abe.

“If Suga lasts, it will be in part due to not being a hereditary politician,” Harris said. “Having worked his way up through politics, he is prepared to work harder and is better able to connect with voters than Abe was. In his own political career, and as Abe’s principal adviser, he has persistently focused on the pocketbook issues that concern voters most.”

Suga’s political fortunes have been closely tied to Abe since he won a lower house seat in 1996, and many cite him as the main influence in Abe’s decision to run for prime minister a second time following a first period in office that ended disastrously after just a year.

Despite the many hours Suga spent briefing, and occasionally clashing, with political journalists, his impassive delivery offered few insights into the man behind the public persona.

But since announcing his candidacy at the end of August, he has undergone a modest image change, from inscrutable political enforcer whose most memorable public act to date was announcing the name of the new Reiwa era last year, to the closest Japan’s dominant conservative party has to the man on the Tokyo omnibus.

“That a regular person like me can seek to become a prime minister … that’s exactly Japan’s democracy, isn’t it?” he said at the start of his campaign.

At 71, Suga is the oldest of the three candidates, but his tireless work ethic is said to extend beyond his life in politics. While he has confessed to a weakness for pancakes, he reportedly burns off the extra calories by beginning and ending each day with 100 sit-ups.