For New Komeito leader Akihiro Ota, the priority in the July 29 election is maintaining the ruling bloc's control of the Upper House, but he won't say if he will resign if the coalition falls short.

Ichiro Ozawa, head of the Democratic Party of Japan, has declared that not only will he step down as party president if the opposition camp as a whole doesn't win a majority, he will retire from politics when his Lower House term is up.

Ota and Prime Minister Shinzo Abe, the Liberal Democratic Party president, have so far refused to put themselves on the line.