Opponents of an oil drilling plan in Ecuador's Amazon rainforest say they're on pace to collect enough signatures to put the proposal up for a national referendum.

A coalition of citizen groups and nongovernmental organizations calling itself YASunidos says it has collected half of the 680,000 signatures required to hold a referendum.

The coalition opposes the government's plan to drill three new oil fields to recover an estimated 900 million barrels of oil. The plan calls for some drilling inside Yasuni National Park, a UNESCO world biosphere reserve that's home to two indigenous groups, the Tagaeri and Taromenane.

Work on two of the oil fields is slated to start next year, with production beginning in 2016. But YASunidos said the public could reject the plan if it makes it onto the ballot.

"We will not rest until we collect at least 800,000 signatures," said Patricio Chavez, a YASunidos coordinator (Mercedes Alvaro, Wall Street Journal, Dec. 10). -- DB