Shigeru Ishiba was essentially confirmed as Japan’s new prime minister on Tuesday, shifting the pressure of managing the nation onto the shoulders of a political idealist who has spent much of his long career offering critiques from the sidelines.

The powerful lower house of parliament approved Ishiba as prime minister in an afternoon vote. The upper house is set to do the same, due to the ruling party’s dominance.

In announcing plans Monday for a national election on Oct 27, Ishiba has already given an indication he’s willing to act decisively to try and turn public support into a mandate to rule. It may also help him stamp his authority on the Liberal Democratic Party (LDP) and the right-leaning party lawmakers who frequently oppose him.

Upheaval in the LDP after a series of scandals and the sidelining of senior power brokers could eventually present Ishiba with an internal challenge, and voter frustration over persistent inflation and the LDP’s past malfeasance may still lead to setbacks at the ballot box.

For now, Ishiba is riding high on a dramatic come-from-behind victory in the LDP leadership election. He’s installed heavyweights in senior roles in the party to try and ensure he has a solid power base, and he’s given up-and-coming LDP election rival Shinjiro Koizumi the job of managing the party’s national election campaigns.

A public opinion poll conducted by the Mainichi newspaper over the weekend showed 52% of those surveyed were optimistic about the incoming Ishiba administration, while 30% expressed pessimism.

Ishiba will announce his cabinet lineup later on Tuesday. Among his picks, Ishiba has handed Katsunobu Kato, another LDP leadership contest rival, the key role of finance minister. Only two women are set to make the cabinet, a fresh reminder of the low levels of representation of women in Japanese politics and professional life.

Ishiba has indicated he will continue many of the economic policies of the outgoing Kishida administration, and the retention of Yoshimasa Hayashi as top government spokesman is one signal of continuity, said Rintaro Nishimura, a Japan associate at The Asia Group, an advisory firm.

A challenge for Ishiba will be managing the right-wing members of the LDP after conservatives were excluded from cabinet and senior party leadership positions, Nishimura said. If he continues to antagonise them, “I fear conservatives will do everything they can to stall or water down Ishiba’s policies,” Nishimura said.

Among Ishiba’s rivals are Sanae Takaichi, who surprisingly lost to Ishiba in a run-off in the LDP leadership election despite leading him in the first round of voting. Takayuki Kobayashi, the other major right-leaning candidate in the LDP election, also missed out on a cabinet position.

Ishiba is expected to hold his own press conference some time in the evening on Tuesday after he visits Emperor Naruhito for a ceremony in which he will be formally confirmed as prime minister.

  - Bloomberg