TOKYO -- A long-serving opposition lawmaker backed by Toyota Motor's labor union will not run in Japan's lower house election on Oct. 31, a decision that comes as the auto industry considers its relationship with the government in an era of stricter environmental restrictions.

Shinichiro Furumoto, who represented Aichi Prefecture's 11th district for 18 years over six consecutive terms, posted on Twitter on Thursday that he "struggled over how to achieve policy goals instead of engaging in interparty strife."

The district covers Toyota's home city. Aichi has long been a stronghold of the old Democratic Party of Japan, which has since split in two, owing to the clout of labor unions there.

Furumoto, himself a former Toyota union member, was a prime example of this strength. He had handily defeated rival candidates over the years with union backing, winning the last election in 2017 by more than 30,000 votes.

But the Toyota union appears to have been reluctant to set itself against the ruling Liberal Democratic Party in the upcoming race. When Furumoto held a news conference Thursday to announce his decision not to run, a union representative also attended to say the group will back no candidates in the district this year.

Shinichiro Furumoto represented Aichi Prefecture's 11th district for 18 years over six consecutive terms.   © Kyodo

With Furumoto officially out, only two candidates -- one from the LDP and another from the Japanese Communist Party -- were running in the district as of Friday.

The shift comes as gasoline and diesel vehicles face mounting headwinds worldwide over climate concerns. Last year, then-Prime Minister Yoshihide Suga set a goal to achieve net-zero greenhouse gas emissions by 2050. The auto industry finds itself at the mercy of the government's strategy for shifting away from fossil fuels.

Within Toyota's union, support has been growing for a comprehensive push toward decarbonization that transcends party lines.

Still, Furumoto's decision sent shock waves among Aichi's other opposition lawmakers, many of whom are backed by other labor unions that are also reevaluating their relationship with their government. It could also affect the electoral strategy of the Confederation of Japan Automobile Workers' Unions, of which the Toyota union is a member.

Tomoko Yoshino this month became the new leader the Japanese Trade Union Confederation, the country's largest labor organization also known as Rengo. Some Rengo members hope she can engage in a dialogue with Prime Minister Fumio Kishida, who appointed her a member of his new expert panel on advancing a "new capitalism."