Banri Kaieda, the trade minister, did nothing for his chances when he broke down in tears under opposition attack.

ECONOMIST: Naoto Kan steps down as prime minister at last

Other possible successors include Finance Minister Yoshihiko Noda and Trade Minister Banri Kaieda.

BBC: Japan PM Naoto Kan announces resignation amid criticism

The newspaper also notes that Noda did not give cabinet positions to two opponents of raising taxes, the previous economics minister, Kaieda, and the transportation minister, Mabuchi.

FORBES: Of Sumo and Japanese Government Finances

But Mr Kaieda's victory is not assured.

BBC: Five candidates battle to succeed Japan PM Naoto Kan