Senior Liberal Democratic Party member Mikio Aoki plans to run for a fifth term in next summer's Upper House election, a decision that could upset reformers within the main opposition party, LDP sources said.
The 75-year-old Aoki, who served as chief Cabinet secretary twice when the LDP was in power, was expected to announce his candidacy in mid-January despite an in-house move to limit the number of candidates aged 70 or older to refurbish the party's image.
Aoki represents Shimane Prefecture and was once called a "kingpin of the Upper House" for his influence within the party over personnel and other affairs related to the chamber.
The LDP does not have an age limit for Upper House candidates running in actual districts, but it does have a retirement age of 70 for lawmakers elected through proportional representation.
