A Brazilian judge has suspended a presidential decree that stripped protections from a reserve in the Amazon and would have allowed mining.
The order, first issued last week and later revised, lifted the reserve designation from a gold-rich area larger than the Netherlands in two northern Brazilian states.
It came under fire from environmental groups who argued it could cause environmental damage and create conflicts between miners and indigenous groups.
President Michel Temer's administration has said mining would not be allowed in conservation or indigenous areas within the reserve.
In a preliminary decision late Tuesday, a judge argued that removing the reserve designation from an area in the heart of the Amazon could only be done with the consent of Congress.
Mr Temer's office said on Wednesday that it would appeal against the decision.