Japanese Prime Minister Shigeru Ishiba on Monday vowed he would stay in office, saying he would not allow a "political vacuum," despite his party's worst election result in 15 years.

Ishiba called Sunday's snap election immediately after he took office on October 1. However, voters irked by a political funding scandal punished his Liberal Democratic Party (LDP), which has governed Japan nearly non-stop since 1955.

What the PM said

While projections showed the LDP-led coalition would likely lose its ruling majority, Ishiba raised the possibility that he could form a minority government.

"I want to fulfill my duty by protecting people's lives, protecting Japan," Ishiba told reporters.

He said the biggest election factor was upset over the slush-fund scandal that sank his predecessor Fumio Kishida. It saw party members pocket funding from fund-raising events, but the money was never declared.

"I am keenly aware that the biggest factor was the failure to report on political funds, and the suspicion, mistrust and anger of the people had not been erased over the issue of money and politics," said Ishiba.

"I will carry out strict reforms within the party and enact fundamental reforms regarding the issue of money and politics," he said.

Japanese media speculated before the election that a poor result for the LDP could see Ishiba potentially quit, making him the nation's shortest-serving prime minister in the post-war period.

Promise to prevent stagnation

Before the election, Ishiba said he was planning a new stimulus package to soothe the pain of rising prices, another contributor to Kishida's unpopularity.

"We cannot allow not even a moment of stagnation as we face very difficult situations both in our security and economic environments," he said at the news conference.

The LDP and its junior coalition partner Komeito won 215 seats in the lower house of parliament — down from 279 seats.

The biggest winner of the night was the main opposition Constitutional Democratic Party of Japan (CDPJ), which had 148 seats — up from 98 previously but still well short of the 233 seats needed for a majority.

The results leave no party with a clear mandate to lead the world's fourth-largest economy, with the yen slipping to a three-month low on the back of political uncertainty.

rc/wd (Reuters, AFP)