The Philippine mining minister's decision to close over half of the country's mines and suspend others is "illegal and unfair," an industry group said, as the minister stood by her action.
Environment and Natural Resources Secretary Regina Lopez on Thursday ordered 23 of the country's 41 mines shut permanently, saying many were operating in watersheds.
The mines to be closed account for half of nickel ore output by the world's top supplier of the metal. Another five mines were suspended.
"She violated due process - which is an inherent part of the rule of law – and did not give proper notice by consistently refusing to release the results of the audit to the affected parties," the Chamber of Mines of the Philippines said in a statement released late on Monday.
A team that reviewed an audit of the mines recommended suspension of operations and payment of fines for environmental violations, rather than closure, two people with knowledge of the matter said.
"Her actions have finally revealed her true bias: to stop all mining in the Philippines," said Artemio Disini, chairman of the chamber.
"It is now apparent that within her department there is widespread chaos," he said, citing conflict between Lopez and the review team from the Mines and Geosciences Bureau. Disini said on Friday the shutdowns would affect 1.2 million people.
The chamber has asked President Rodrigo Duterte to review Lopez's action, calling it "without basis, fairness and legality."
Duterte has supported Lopez's move and the minister said she will not reconsider her decision, adding the Southeast Asian nation is "unfit for mining."
"These open pits near our rivers and streams will be there forever and a day," Lopez told Reuters.
"How is that economically lucid? It's crazy, why are we doing this?"
A staunch environmentalist, Lopez launched an audit of the country's mines in July, shortly after being sworn in, aiming to punish operations she thinks are harming the environment.
Still largely unexplored, the Philippines' mining sector contributes less than 1 percent to the overall economy.
Only 3 percent of 9 million hectares identified by the state as having high mineral reserves is being mined, according to government data.