Lawmakers in Ecuador have authorised the extraction of oil from Yasuni National Park, a pristine Amazon reserve.
After a 10-hour debate, congress on Thursday approved the motion backed by President Rafael Correa by a 108 to 25 margin, with four legislators absent.
Correa in August announced that he was abandoning a unique plan to persuade rich countries to pay Ecuador not to drill in the Yasuni, saying wealthy nations had failed to pledge enough money.
Environmentalist hailed the initiative when it was announced in 2007, saying Correa was setting a precedent in the fight against global warming by lowering the high cost to poor countries of preserving the environment.
Correa had sought $3.6bn in contributions to maintain a moratorium on Yasuni drilling. But he said Ecuador managed to raise just $13m.