An amendment to the 2010 financial reform law, known as Dodd-Frank, requires oil and mining companies listed by the Securities and Exchange Commission to release information about payments to U.S. and foreign governments.
Oxfam Senior Policy Director Ian Gary said the group was watching the SEC.
"Our campaign aims to send a strong message that we're watching and ready to fight back if the regulatory agency issues weak final rules," he said in a statement.
Democratic lawmakers last month warned against an industry-led effort to soften those rules.
Earthrights International said trade groups like the American Petroleum Institute are making "wild claims" that U.S. jobs would be lost without concessions from the SEC.
Paul Donowitz, a campaign director for Earthrights International, said energy companies' support for transparency disappears as soon as it comes time to open their books.
"We do expect and demand more from our government and we'll be watching the SEC very closely to make sure they are not swayed by the scare tactics of API and their oily friends," he said in a statement.