A dozen congressional Democrats are pushing the U.S. Securities and Exchange Commission to move ahead with a new rule that orders companies to report whether their goods have “conflict minerals” from the Democratic Republic of Congo, despite a federal appellate court ruling that cut some of the regulation.

In an April 21 letter that became public Tuesday, six senators and six House members told SEC chairwoman Mary Jo White that the agency shouldn’t postpone the implementation of the rule, which is set to take effect June 2. Sens. Dick Durbin of Illinois, Tim Johnson of South Dakota, Ben Cardin of Maryland, Barbara Boxer of California, Sherrod Brown of Ohio, Ed Markey of Massachusetts, as well as Reps. Jim McDermott of Washington, Maxine Waters of California, Raul Grijalva of Arizona, Jim Moran of Virginia, John Lewis of Georgia and Gwen Moore of Wisconsin all signed the letter.