Former Nagano Gov. Yasuo Tanaka, who heads the minor political party New Party Nippon, officially said Monday he will be a candidate in July's House of Councilors election.
Speaking at a news conference in Tokyo, Tanaka said he and journalist Yoshifu Arita will seek seats under the proportional representation system, where voters across the country can cast ballots either for the candidate or the party fielding them.
The party will aim to field candidates in Tokyo and Osaka districts, as well as in the nationwide constituency under the proportional representation system.
Tanaka was first elected Nagano governor in October 2000 and won re-election in 2002 after accepting a no-confidence motion from the prefectural assembly.
However, he lost in 2006 to former veteran lawmaker Jin Murai.
Tanaka has headed New Party Nippon since it was established in August 2005 by lawmakers opposed to then Prime Minister Junichiro Koizumi's postal privatization legislation.