Prime Minister Fumio Kishida faces his first electoral test after making Cabinet and Liberal Democratic Party leadership changes last month. Two by-elections on Sunday are being closely watched for their impact on his leadership strength during the fall session of parliament as well as the odds of Kishida calling a snap election before year-end.

A Kyodo News poll released earlier this week showed a close race in the Lower House Nagasaki No. 4 by-election, which pits LDP member Yozo Kaneko, 40, who is also endorsed by Komeito, against Seiichi Suetsugu, 60, a member of the Constitutional Democratic Party of Japan and a former Lower House proportional representative for Kyushu. He also has the support of the Social Democratic Party and less formal support from the local chapters of the Japanese Communist Party and Democratic Party for the People.

The other race is an Upper House contest for the Tokushima-Kochi seat. Former Kochi prefectural assembly member Ken Nishiuchi, 56 — now an LDP member also endorsed by Komeito — is competing against independent Hajime Hirota, 55, a former two-term Upper House member and then one-term Lower House member who was voted out of office in 2021 after one term. The Kyodo poll showed Hirota, endorsed by the CDP and enjoying strong support from other opposition parties, leading Nishiuchi.