Katsuya Okada, deputy leader of the Democratic Party of Japan, is considering running in the party's Jan. 18 leadership race to replace outgoing President Banri Kaieda.
Former Secretary-General Goshi Hosono has already thrown his hat into the ring.
The next leader of the largest opposition party will have to jump-start the rebuilding process after the Liberal Democratic Party-Komeito ruling coalition retained its two-thirds supermajority in the Dec. 14 House of Representatives election and took Kaieda's Diet seat along the way, forcing him to resign.