A man prays as he mourns former Japanese Prime Minister Shinzo Abe, who was shot while campaigning for a parliamentary election, outside his residence in Tokyo, Japan July 9, 2022.
A man prays as he mourns former Japanese Prime Minister Shinzo Abe, who was shot while campaigning for a parliamentary election, outside his residence in Tokyo, Japan July 9, 2022. Reuters / KIM KYUNG-HOON

Japan's ruling coalition was projected to keep its majority in the upper house of parliament on Sunday, two days after the assassination of former Prime Minister Shinzo Abe, a dominant politician and power broker.

Prime Minister Fumio Kishida's Liberal Democratic Party (LDP), of which Abe was a senior figure, and its junior coalition partner Komeito were on track to win between 69 and 83 of the 125 seats contested in Sunday's vote, according to an exit poll by public broadcaster NHK.

Official results are expected on Monday.

Abe, Japan's longest-serving modern leader, was gunned down on Friday during a speech in support of a local candidate in the western city of Nara, a killing the political establishment condemned as an attack on democracy itself.

Analysts predicted the assassination would boost the LDP, led by Prime Minister Fumio Kishida, an Abe protege.

The party was projected to win 59 to 69 of the upper house seats contested, according the exit poll, up from the 55 it held previously. Reaching 69 seats would give the LDP a majority on its own, a threshold seen as a stretch before Abe's killing.

"Former Prime Minister Abe, who came to support me, was shot in an act of terrorism in the midst of our election campaign," LDP candidate Kei Sato said after NHK projected he would win his seat in Nara prefecture. Abe was stumping for Sato when he was shot.

"But we continued our campaign in the belief that we must not cave into terrorism or fear it - we must overcome it. I hope to travel to Tokyo tomorrow to tell former Prime Minister Abe himself of this victory," he said.

Elections for parliament's less powerful upper house are typically seen as a referendum on the sitting government. Change of government was not at stake, as that is determined by the lower house.

A strong showing at the polls could help Kishida consolidate his rule, giving the former banker from Hiroshima a chance to carry out his goal of boosting military spending.

It might allow him to revise Japan's pacifist constitution, a dream Abe never achieved.

The exit polls show parties open to revising the pacifist constitution were projected to maintain their two-thirds majority in the upper house. Most voters favour greater military strength, opinion polls show.

Kishida may move cautiously on constitutional change, but the apparent victory looked set to pave the way for more defence spending, a key LDP election promise, said Robert Ward of the International Institute of Strategic Studies.

Kishida "now has a green light for this", Ward said.

Security has ramped up since Abe's assassination. Police arrested a 41-year-old man immediately after Abe was shot at close range with a homemade gun.

There was an increased police presence for Kishida on Saturday at a campaign event in a city southwest of Tokyo and a metal detection scanner was installed at the venue, an unusual security measure in Japan.