The government of Okinawa Prefecture has decided to revoke on Friday a landfill permit it granted for building a new US Marine Corps base in a coastal area of Nago City.
Okinawa made the decision on Thursday, to block the construction.
The land is being reclaimed to relocate the US Marine Corps Futenma Air Station in a densely populated area of Ginowan City, also in Okinawa Prefecture.
Without the permit, the reclamation work will have to be stopped. Japan's government is expected to take legal action to nullify Okinawa's decision.
The prefectural government initially planned to revoke the permit earlier. Former prefectural governor Takeshi Onaga announced late last month that he would start procedures for doing so.
The prefecture had planned to issue the revocation before August 17th -- the date set by the central government for the start of work to dump soil and sand at the site.
But it put its final decision on hold as Onaga died of cancer on August 8th and the central government postponed the dumping.
Okinawa has now decided that it will fulfill the late governor's dying wishes by revoking the permit.
The prefecture's 2 vice governors are to explain the reasons for its decision at a news conference on Friday.
Environmental concerns are expected to be cited a major factor.
The central government has held off on the work due to opinions in the ruling parties and the government that it is better to wait until after Okinawa holds a gubernatorial election on September 30th.
The central government appears to want to begin the reclamation work soon after the election. It is expected to ask courts to nullify Okinawa's decision to revoke its landfill permit for that purpose.