Prosecutors in the classified information case against two former AIPAC staffers want to keep the defense’s most potentially damaging expert witness from testifying. The motion to bar testimony from William Leonard, until last year the government’s classification czar, also suggests that the prosecution will seek to bar any former government official from testifying as an expert in the case against Steve Rosen, the American Israel Public Affairs Committee’s former foreign policy chief, and Keith Weissman, its former Iran analyst. Prosecutors say in the March 31 filing obtained Friday by JTA that the court has no authority to compel Leonard’s testimony and that he is ethically and legally bound not to testify. The filing cites a number of laws, one banning for two years expert defense testimony from government officials in cases where the United States is a party, others banning it permanently. It also cites criminal penalties for such testimony of up to five years, and suggest that seven of eight expert witnesses for the defense â€“ all former government employees – may all be ineligible to testify. “The statutory restrictions enumerated here may likewise apply to other expert witnesses the defense intends to present,” the petition says. Leonard, the filing says, is especially susceptible because as the director of the Information Security Oversight Office until last year he consulted with prosecutors on the case. “Mr. Leonard participated personally and substantially not only in this very matter, but in this very litigation in his discussion with the government prosecution team,” the filing says. The agreement last month of Leonard and his predecessor, Steven Garfinkel, to testify stunned the community of those who track secrecy laws. “The fact that they are testifying for the defense is a startling indication that the prosecution’s case has strayed far beyond any consensus view regarding the proper protection of classified information,” Secrecy News, the preeminent blog on the topic, wrote at the time. Both men, whose job involved determining what should and shouldnâ€™t remain classified, have been outspoken in private life in arguing that the government tends to over-classify. If Judge T.S. Ellis III upholds the motion, it could create an imbalance; prosecutors have secured three current and former senior government officials who deal with classification to testify on the government’s behalf. Lawyers for the defense were unavailable late Friday for comment. They have until April 11 to reply. The government indicted Rosen and Weissman in August 2005 for allegedly receiving classified information about Iran and terrorism and relaying it to journalists, their colleagues and Israeli diplomats. The section of the 1917 statute under which they were charged makes civilians criminally liable if they receive or disseminate classified information. It has never been the exclusive basis for a prosecution, in part because of the First Amendment entanglements it entails.The trial has yet to come to court.