TOKYO –

said on Sept 7 that he would resign, caving in to ruling party pressure on him to take responsibility for a series of election losses, most recently in July’s Upper House polls.

Mr Ishiba’s resignation will trigger a leadership race in his Liberal Democratic Party (LDP), with the winner facing a Parliament vote to become prime minister.

Since the ruling coalition has lost its majorities in both Chambers of Parliament, the LDP president is no longer guaranteed to become premier. There is a slim possibility that an opposition party leader will take the helm of one of the world’s largest economies.

Here is a list of lawmakers who might throw their hats in the ring:

Ruling: LDP

Sanae Takaichi, 64

If chosen, Ms Takaichi would be Japan’s first female prime minister.

A party veteran who has held a variety of roles, including that of economic security and internal affairs minister, she lost to Mr Ishiba in the LDP leadership race in a run-off vote in 2024.

Known for conservative positions such as revising the pacifist post-war Constitution, Ms Takaichi is a regular visitor to the Yasukuni shrine to honour Japan’s war dead, viewed by some Asian neighbours as a symbol of past militarism.

Ms Takaichi stands out for her vocal opposition to the Bank of Japan’s (BOJ) interest rate hikes and her calls to ramp up spending to boost the fragile economy.

Shinjiro Koizumi, 44

Heir to a political dynasty that has had a hand in governing Japan for more than a century, Mr Koizumi would become its youngest prime minister in the modern era.

Mr Koizumi ran in the 2024 party leadership race, presenting himself as a reformer able to restore public trust in a scandal-hit party.

Unlike Ms Takaichi, who left government after her defeat in that contest, the Columbia University-educated Koizumi stayed close to Mr Ishiba as his agriculture minister, overseeing a widely publicised attempt to curb soaring rice prices.

In his only other Cabinet post as environment minister, Mr Koizumi called for Japan to get rid of nuclear reactors in 2019. He faced ridicule that year for remarks that climate policy needed to be “cool” and “sexy”. Little is known about his views on economic policy, including on the BOJ.

Yoshimasa Hayashi, 64

Mr Hayashi has been Japan’s Chief Cabinet Secretary, a pivotal job that includes being top government spokesman, since December 2023 under then Premier Fumio Kishida and Mr Ishiba.

He has held a variety of portfolios, including as defence, foreign and agriculture minister, often being tapped as a pinch hitter following an incumbent’s resignation.

A fluent English speaker, Mr Hayashi worked for trading house Mitsui & Co, studied at the Harvard Kennedy School, and was a staff member for US Representative Stephen Neal and Senator William Roth Jr.

Mr Hayashi ran for the LDP leadership race in 2012 and 2024. He has repeatedly called for respecting the BOJ’s independence on monetary policy.

Opposition: Constitutional Democratic Party of Japan

Yoshihiko Noda, 68

Former prime minister Noda is the leader of the biggest opposition group, the centre-left Constitutional Democrats.

As premier from 2011 to 2012, he worked with the LDP to push through legislation to double Japan’s consumption tax to 10 per cent to help curb bulging public debt – earning a reputation as a fiscal hawk. The consumption tax was raised to 10 per cent in 2019 for most items.

In the Upper House election in July, Mr Noda reversed course and called for a temporary cut to the consumption tax for food items. He has repeatedly called for phasing out the BOJ’s massive stimulus.

Opposition: Democratic Party for the People

Yuichiro Tamaki, 56

Mr Tamaki’s centre-right party is one of the fastest-growing in recent elections.

A former Finance Ministry bureaucrat, Mr Tamaki co-founded the Democratic Party for the People in 2018 and advocates increasing people’s take-home pay by expanding tax exemptions and slashing the consumption tax.

He supports boosting defence capabilities, stricter regulations for foreigners’ land acquisition and building more nuclear power plants.

Mr Tamaki has called on the BOJ to be cautious about phasing out stimulus, saying it should wait until real wages turn positive and help underpin consumption. REUTERS