TOKYO — Japan’s governing party on Monday anointed Yoshihide Suga, the current chief cabinet secretary, as its choice for the next prime minister, settling on what it saw as a safe pair of hands to grapple with the country’s many economic and strategic challenges.
Two weeks after Prime Minister Shinzo Abe said he was stepping down after a record-long tenure, Mr. Suga was overwhelmingly elected as leader of the conservative Liberal Democratic Party during a conclave of members of Parliament and select delegates at a luxury hotel in central Tokyo.
The party handily controls Parliament, virtually guaranteeing that Mr. Suga, 71, will be elected prime minister this week during a special session of the legislature.
Monday’s vote put the party’s imprimatur on a decision that had been made not by its broad rank and file, but was instead negotiated in the back rooms of Tokyo’s political elite, perhaps well before Mr. Abe had even decided to resign late last month.
Mr. Suga became the odds-on favorite to succeed Mr. Abe not long after the prime minister’s announcement. A path was cleared for him inside the party when his most serious competitor, Taro Aso, the deputy prime minister and a former prime minister, said he would not stand for election.
Mr. Aso, a sharp-elbowed political boss with a history of hair-raising gaffes, controls one of several major factions within the party. His decision to stand aside for Mr. Suga raised suspicions that the move was part of a quid pro quo that would grant him some control over choosing the new cabinet.
Mr. Suga’s front-runner standing was further solidified days later, when the party’s secretary, Toshihiro Nikai, announced that he would invoke an emergency provision in the organization’s bylaws to exclude rank-and-file members from voting for the new leader.
That decision, which restricted the party election to serving members of Parliament and three representatives from each prefecture, effectively shut out Shigeru Ishiba, the one dark horse candidate who could have posed a challenge to Mr. Suga.
Mr. Ishiba, a former defense minister who consistently had the highest approval ratings among the declared candidates, is disliked by many party insiders because of his criticism of Mr. Abe’s policies. Mr. Abe narrowly defeated Mr. Ishiba in the party’s 2012 leadership election.
Mr. Suga has served as Mr. Abe’s chief cabinet secretary for nearly eight years, a position that combines the power of a chief of staff with the public visibility of the country’s top spokesman. Behind the scenes, he has been a key figure in the creation and implementation of national policy during the Abe administration.
Now, as prime minister, Mr. Suga will have to hit the ground running. He will take office in the middle of a global pandemic that has devastated Japan’s economy, effectively erasing years of growth under Mr. Abe.
The country is also facing deepening pressure from China and North Korea. And it is losing a prime minister who built his foreign policy legacy in part on his successful management of President Trump, the mercurial leader of Japan’s most important strategic ally.
Mr. Suga’s attention in the near term is most likely to be consumed by the country’s economic problems, said Atsuo Ito, an independent political analyst. That makes it less clear how forcefully Mr. Suga will pursue Mr. Abe’s security policies, such as pushing for Japan to amend its pacifist Constitution.
With Mr. Suga’s election, his party is hoping to soothe a public worried that the prolonged political stability of the Abe era could crumble. Before Mr. Abe’s election in 2012, the country burned through six prime ministers in six years.
Mr. Suga has said that he plans to continue Mr. Abe’s policies largely unchanged. On the economy, that means loose monetary policy, aggressive fiscal stimulus and the overhaul of Japan’s sclerotic bureaucracy and corporations. Among those policies is a program aimed at making it easier for women to join the work force — efforts that have met with mixed results.
The party also chose Mr. Suga as a way to protect the power and prerogatives it had built up under Mr. Abe, Mr. Ito said.
“He won’t fundamentally change the structure of the Abe administration,” he said.
Mr. Suga’s victory on Monday earned him a spot at the top of the party through the end of Mr. Abe’s current term in September 2021. At that time, Mr. Suga would have to stand again for the L.D.P. presidency in a regular party election.
Political analysts believe he may seek to solidify his position by calling a snap election as early as next month. Although Mr. Suga has said he will not call an election until the coronavirus is under control, party heavyweights, including Mr. Aso, have raised the possibility.
Public opinion, which had been severely critical of Mr. Abe’s handling of the pandemic, has become more forgiving as infection numbers have remained relatively low and nostalgia has set in. Mr. Suga may hope to profit from the recent bounce in Mr. Abe’s poll numbers, which have risen from the mid-30s to as high as the mid-50s in recent days, according to polling by Kyodo News.
Mr. Suga is a career politician who grew up in a hardscrabble Japanese town. He became a cabinet minister in Mr. Abe’s brief first administration in 2006, before taking his place as Mr. Abe’s top fixer following his re-election in 2012.
His popularity grew last year when he unveiled the official name for Japan’s new imperial era. Photos of Mr. Suga holding up a hand-painted sign emblazoned with the word “Reiwa” showed a human side to a man best known to the public for the phlegmatic twice-daily news conferences he gave as Mr. Abe’s cabinet secretary.