Oxfam America has filed a motion to intervene in a lawsuit filed last month by the U.S. Chamber of Commerce and oil companies over a new requirement that they disclose payments made to governments in exchange for extraction rights.

The law in question, known as Section 1504 or the Cardin-Lugar Amendment of the Dodd-Frank Act requires oil, gas and mining companies to disclose payments they make to U.S. and foreign governments for natural resources extraction. The Securities and Exchange Commission issued a final rule on the disclosure mandate on Aug. 22. Among the groups seeking to overturn the law and block implementation was the American Petroleum Institute, which represents, among other companies, Shell, Chevron, BP, and Exxon.

Oxfam America's motion to intervene argues that API's lawsuit would negatively impact its mission to “ensure citizens in oil and mineral rich countries know how much money their governments receive from the extraction of oil and minerals.” Because the organization also holds stock in oil companies (including Chevron and Exxon), the motion argues that the lawsuit undermines its status as an investor.

Among the ammunition used by Oxfam America to bolster its case is a recent review by Congress' Government Accountability Office. It concluded that the SEC "complied with applicable requirements in promulgating" the final rule for Section 1504.

Investors worth more than $1.2 trillion have also weighed in with the SEC, asking the agency to quickly implement a final rule that followed the statutory language and Congressional intent, the organization says, adding that several companies already disclose payments in every country of operation, often at the project level as the final rule requires. "If payment disclosures hurt bottom lines, then leading companies like Statoil and Talisman Energy would not already be disclosing this type of information," Ian Gary, senior policy manager of Oxfam America's oil, gas and mining program, said in a statement. "Any well-run company should already collect and account for this information and if systems aren't in place for tracking payments, investors need to ask why."

In May, prior to August's vote, Oxfam America sued the SEC over delays in implementing the Dodd-Frank requirement.