Former trade minister Isshu Sugawara resigned as a lawmaker on Thursday after coming under investigation again over a money and gift scandal that prosecutors had once dropped.

The House of Representatives approved the resignation of Sugawara, who left the ruling Liberal Democratic Party the previous day. Prosecutors are arranging to issue a summary indictment on him for violation of the election law, according to a source close to the investigation.

Isshu Sugawara. (Kyodo)

There will be no by-election for the seat vacated by Sugawara as a general election will be held later this year with lower house members' terms running out on Oct. 21.

Sugawara's resignation deals a blow to Prime Minister Yoshihide Suga, who had pushed for Sugawara to become trade minister in September 2019 before he quickly stepped down over the scandal the following month.

Concerned about the impact of the scandal on a July election for the Tokyo metropolitan assembly and the lower house election, LDP executives had been making arrangements behind the scenes for Sugawara's resignation.

Sugawara was questioned by prosecutors after a civil inquest body decided in February that he merits indictment. His office is alleged to have offered money and gifts to supporters between 2017 and 2019 in violation of the election law.

The Public Offices Election Law prohibits politicians from making donations to voters in their constituencies, except for money given in person by lawmakers at ceremonies such as weddings and funerals, and violators are fined up to 500,000 yen ($4,500).

The House of Representatives plenary session during which the resignation of former trade minister Isshu Sugawara was approved is pictured on June 3, 2021. (Kyodo)

Sugawara has likely decided to resign since a lawmaker loses his or her seat once a fine or more severe penalty is finalized, according to sources familiar with the matter.

The summary indictment he may face is a simplified procedure that skips court proceedings and applies to less serious offenses.

In June last year, the special investigation squad of the Tokyo District Public Prosecutors Office decided not to indict Sugawara for giving condolence money and flowers totaling 300,000 yen through his secretary and others to 27 voters from 2017 to 2019.

But the Committee for the Inquest of Prosecution overturned the decision. Such panels, composed of voters chosen by lottery, are set up to review decisions by prosecutors not to put a suspect on trial if that decision is challenged.