Osaka Mayor Toru Hashimoto has dropped out of national politics, at least for now, to concentrate on his plan to integrate Osaka city and prefecture and to cease being an obstacle, he says, to a grand realignment of like-minded opposition politicians.

"What's necessary are two large, strong parties. Within the Democratic Party of Japan, strong voices are saying (Ishin no To and the DPJ) could come together if Hashimoto is not involved. If opposition realignment will progress without me, I'd like it to go ahead," Hashimoto told reporters in Osaka on Wednesday.

Many in Ishin have expressed reservations about joining forces with the DPJ. Among them are Kenji Eda, who became party president after Hashimoto's resignation as co-leader.