With no permission to build anywhere as of yet, the developer of the planned Thirty Meter Telescope announced Friday it will delay its decision about where to construct its $1.4 billion next-generation observatory.

Hawaii’s tallest mountain, Mauna Kea, is still the preferred site, but the Canary Islands remains a viable alternative, according to the TMT International Observatory Board of Governors, which met in California this week.

“In order to chose a site, we need permits,” said Ed Stone, the organization’s executive director. “We don’t have the permits at either site, so we have no choice but to wait.”

However, with progress being made in the legal and regulatory arenas of both proposed sites, Stone said he is hopeful a decision can be made later this year.

TMT officials have been saying for months that a final decision would be made in April. Before that they were insisting that construction actually start atop the 13,796-foot mountain this month.

But the replay of a contested case hearing — ordered by the state Supreme Court for a violation of due process — dragged on, and the regulatory hurdles in the Canary Islands haven’t been as easy to clear as first thought, Stone said.

“None of us realized the contested case hearing would take 44 days of hearings and run over five or six months,” he said.

Newspapers in Spain and the Canary Islands last month reported that members of the TMT governing board assured local officials that the decision of where to build would be delayed until November. And state Sen. Kaiali‘i Kahele (D, Hilo) said TMT officials told him they needed assurances of site access by late summer or early fall.

Stone would not confirm any deadline dates Friday, saying the governing board would evaluate the best move forward based on factors as they arise.

In Hawaii there are two appeals before the state Supreme Court. The state Board of Land and Natural Resources voted last fall to reissue a conservation district use permit that would allow construction on Mauna Kea, but it was appealed to the high court.

While legal briefs have been filed in that case, oral arguments for the other appeal, involving the project’s sublease, were held before the court in March.

“TMT is grateful that the legal process is moving forward in Hawaii and we remain hopeful of court decisions that will allow us to resume construction on Maunakea,” TMT Chairman Henry Yang said in a news release. “We remain respectful of and will continue to follow the legal and regulatory processes.”

Stone, a physics professor at the California Institute of Technology, said officials are encouraged by growing public support in the islands. That support was seen in a recent Honolulu Star-Advertiser poll showing strong statewide backing for the TMT, even among Native Hawaiians.

But he denounced an attempt by state lawmakers to impose a moratorium on summit construction.

“Any further delay like a moratorium would be a very serious setback for building the TMT on Mauna Kea,” he said.

The state Senate voted Thursday in favor of a ban on new construction atop Mauna Kea, pending the completion of overdue regulatory requirements. But House leaders vowed to block the effort, saying any impediments should not be placed on the TMT at this juncture.

In the Canary Islands, meanwhile, an environmental impact assessment for the TMT on La Palma island has been submitted to the local government. A public review process is expected to continue into the summer. Once the document is accepted, permits for construction and other clearances will be applied for, Stone said.

Stone said that while the TMT does face some opposition in the Canaries, it’s hard to say whether it will lead to any appreciable delay in the governmental review process.

“We’re hopeful that’s not the case,” he said, “but time will tell.”

The University of Hawaii, the Mauna Kea lessee that has guided the landmark TMT through the regulatory process here, welcomed the additional time.

“This is certainly good news for Hawaii and the university, but for us, TMT is just part of a much larger issue. It’s a privilege to practice astronomy on Maunakea and we’re not satisfied with where we’re at right now. We will continue to push ourselves to improve our stewardship of the mountain and we hope to have more information on those efforts in the months to come,” UH spokesman Dan Meisenzahl said in a statement.

Project foes, meanwhile, have promised to continue to oppose the TMT, even if they have to block construction crews on the mountain, as they did successfully on three occasions in 2015.

The project has been billed as the most powerful optical telescope in the world, capable of seeing the origins of the universe more than 13 billion light-years away.

The next meeting of the TMT board of governors is in August. The board meets four times a year.