The 46,450 square kilometre reserve is more than twice the size of New Jersey State and is thought to be rich in minerals such as copper and gold.

However, following public outrage, the federal court of Brasilia said Thursday that it had "partially granted an injunction to immediately suspend any administrative act" aimed at opening up the three-decades-old reserve.

A decree from President Michel Temer published last week planned to abolish the protected status of the National Reserve of Copper and Associates (Renca), which is split between the Northern Brazilian states of Amapa and Para.

A Brazilian court has suspended plans to dismantle an Amazonian national reserve twice the size of New Jersey, which would have opened the area up to mining.

Just under a third of the area (30 percent) was expected to be opened up to mining, which the government said will help create jobs, generate income and combat illegal mining. But activists argued that the move could damage the world's largest and most diverse tropical rainforest.

In a statement released last Wednesday, the government said permission to conduct mining would only be granted in areas not currently used for vegetation or homes.

"Permission to develop research and mining applies only to areas where there are no other restrictions, such as protection of native vegetation, conservation units, indigenous lands and areas in border strips."

However, Brazilian public policy coordinator of the World Wide Fund for Nature (WWF), Michel de Souza, said at the time that the announcement was a "catastrophe", which failed to consult the public and could leave the region vulnerable to corruption and conflict, O Globo reported.

The plans later prompted widespread campaigning by activists, celebrities, and Brazil's influential Catholic hierarchy, who criticized the plans.

Judge Ronaldo Spanholo, who ordered the suspension, said Wednesday that the government's plans were unconstitutional as they had failed to consult Congress, and added that the decree would "put at risk the environmental protection (of Renca) and the protection of local indigenous communities."

The government has said it will appeal the decision.

A report released by the WWF earlier this month warned that mining in the area would cause "demographic explosion, deforestation, the destruction of water resources, the loss of biodiversity and the creation of land conflict".

Renca has been protected from private mining since it was established as a national reserve in 1984.

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