Seabed mining company Trans-Tasman Resources has formally asked the Environmental Protection Authority to reconsider its consents to mine iron-sand offshore from Pātea.
The authority received the request on October 22, general manager climate, land and oceans Michelle Ward said.
It is now clarifying with the High Court how that process will work.
"We are unable to comment further until we receive clarification," she said.
Trans-Tasman Resources wants to suck up 50 million tonnes of iron-sand a year from the South Taranaki seabed, 22km to 36km offshore from Pātea.
It would then export up to five million tonnes a year of vanadium-rich titanomagnetite iron-sand, returning the rest to the sea floor.
An Environmental Protection Authority (EPA) decision-making committee narrowly granted marine and discharge consents in 2017.
After that they were fought through New Zealand courts by a combined group of iwi, environmental and fishing interests.
On September 30 the Supreme Court found the EPA was wrong to grant the consents, but that they could be reconsidered.
Trans-Tasman Resources needs the consents so that it can begin the final development phases of the iron-sand mining project.
Opposition groups say the company will be unable to prove the mining can be done without harming the environment.
TTR executive chairman Alan Eggers said he was unsure how long the process to reconsider the consents would take.
"We are in an area of unknown and uncharted territory here. It could take weeks, if not months or years.
"It's certainly a protracted process that, in our view, shouldn't be happening."
He said he would welcome "the end of this endless environmental litigation about points of law".
"We would just like to get on with our lawful process of finalising our environmental approvals, and get on with developing the project for the benefit of the region and TTR's investors."
Spokeswoman for South Taranaki iwi Ngāti Ruanui, Debbie Ngarewa-Packer, said for TTR to get its consents approved it would need evidence the project was not destructive.
She said Ngati Ruanui and other opposers now had the right to seek High Court direction on any part of the company's application.
Environmental group Kiwis Against Seabed Mining will be among those doing so, chairwoman Cindy Baxter said.
The Supreme Court was clear that seabed mining would cause too much environmental harm, she said, and opposition groups are tired of fighting the matter.
"None of us want to be dragged through another lengthy process.
"So we reiterate our call on the Government to step in and ban seabed mining in New Zealand waters."