Brazil's lower house of Congress has approved a measure significantly reducing the size of a fully protected national park in the Amazon rain forest and opening up a big chunk of land for agriculture and other activities.

Lawmakers agreed Tuesday night to convert 1.2 million acres of the 3.2 million-acre Jamanxim National Park in Para state into what is called an environmental protection area. That would let the land be used for the extraction of lumber, agriculture and mining — activities not allowed in a fully protected national park.

The legislation is seen as a victory of Congress' rural lobby representing agribusiness. It now goes before the Senate and would also have to be ratified by President Michel Temer to take effect.

Environmentalists fear the move will lead to a rise in deforestation and to a wave of illegal occupations.

"Congress' decision comes at a time when deforestation is increasing," Christine Mazzetti of Greenpeace Brazil said by telephone, referring to last year's 30 percent rise in deforestation in the Amazon rain forest.

"Now is the time to create more conservation units, but instead, Brazil is reducing them," she said. "It is moving in the opposite direction in the name of economic development."

She said that soon after the Jamanxim National Park was created, land grabbers invaded parts of it, clearing land for agriculture, cattle raising and mining. Congress' decision will benefit them and encourage others to the same in other conservation areas, Mazzetti said.

She said the decision had the potential to spark more land disputes.

Disputes over land involving indigenous groups, loggers, ranchers and small-scale farmers frequently turn violent in Brazil. Last year, 61 people were killed in violence stemming from such fights, according to the Brazil-based Pastoral Land Commission of the Catholic Church. Of this total, 13 were members of indigenous groups.

Requests for comment from government environmental protection agencies went unanswered.