Former Prime Minister Tomiichi Murayama formally announced Saturday that he will not run in the House of Representatives general election later this year.
Murayama, 76, former leader of the Social Democratic Party, was elected from the No. 1 Oita constituency.
"I've decided not to run in the next general election. I hope you will understand my decision," he told a general meeting of his supporters.
Murayama later told a press conference: "I felt I have reached the limits of my spiritual drive and physical capability. I have said from two elections ago that this would be my last term, and I want to keep my word."