The spate of victories logged so far by ruling bloc-backed candidates in the unified local elections underlines the strength of Prime Minister Shinzo Abe's Liberal Democratic Party and the weakness of the top opposition force, the Democratic Party of Japan.

Media reports say the victories will give him more momentum to push unpopular bills through the Diet and boost his chances for re-election in the LDP's presidential race in November, which would see his tenure extended by three more years.

In a possible sign that victory was anticipated in first round of races held Sunday, LDP Secretary-General Sadakazu Tanigaki, a dove and potential rival to the hawkish prime minister, told reporters Thursday he would support an Abe re-election bid in November. Another powerful LDP executive, Toshihiro Nikai, has already expressed support for Abe.