Osaka Gov. Ichiro Matsui announced Monday that a second referendum on whether to merge Osaka's wards might be held during the nationwide local elections in April 2019, six months later than the governor and his supporters originally hoped for.

"We haven't given up on a referendum this autumn. But no matter how delayed, we want a decision to be made on the merger plan within the term of the current Osaka prefectural and municipal assemblies," Matsui told reporters.

The elections, including those for Osaka's assemblies, are expected to be held a year from now. Matsui heads both the national party Nippon Ishin no Kai as well as Osaka Ishin no Kai (One Osaka), a local political group that has a plurality but not a majority in both the municipal and prefectural assemblies. To form a majority, Osaka Ishin must work with Komeito.