"It is important that we consider and understand the impact that this proposal will have on the various sectors of the U.S. economy as well as consumers and young people," the letter concludes. "Thus, we look forward to receiving the [Interagency Working Group's] response to these important questions. In the interim, we ask that you withhold any further action, except for the process of analyzing comments to the proposal."
The letter is signed by 18 Republicans and Sen. Ben Nelson (D-Neb.).