Critics of a Justice Department memorandum that some say is forcing companies to routinely waive attorney-client and work-product protections—and cut off financial support for employees under investigation in order to curry favor with federal prosecutors—took their calls for reform to Capitol Hill recently, while a top Department of Justice official defended the memo’s principles and the tactics used by prosecutors.

Even as he reiterated his support of the so-called Thompson Memo during recent testimony before a Senate committee, Deputy Attorney General Paul McNulty appeared to leave the door open for future changes, which could alter the way prosecutors pursue companies and white-collar defendants.