Regulators and central bankers from the U.K., Canada and Japan have already voiced concerns with U.S. officials about the Volcker rule, and other foreign entities are expected to follow suit. The European Commission reportedly plans to speak with officials at the Treasury Department. Rob Toomey, managing director and associate general counsel at SIFMA, said the group backs calls to exempt sovereign-debt trading. "We spot-on agree with the positions taken by these foreign authorities -- how they are viewing the restrictive interpretation of market making and how that impacts their debt," Toomey said. See SIFMA's Volcker Rule Resource Center, including two recent studies on the impact of the proposed rule.