Mr. Muris and Charles James, assistant attorney general for antitrust, are expected to face heavy criticism from Sen. Ernest "Fritz" Hollings about the deal they made in which the FTC ceded all oversight of media mergers to the Justice Department.
Sen Hollings has been critical of the deal, suggesting that it will result in less intensive and less independent scrutiny of the mergers.
The South Carolina Democrat has also questioned the process by which the deal was reached, noting the wording of the agreement was crafted by an industry lawyer who represented AOL Time Warner during the FTC's tough scrutiny of its merger. Sen. Hollings also chastised the two officials for not consulting consumer groups before the deal was announced.
Sen. Hollings earlier warned the FTC that it could face stiff budget cuts if the deal wasn't abandoned.