The director of the Central Intelligence Agency concluded in late 2005 that a conversation picked up on a government wiretap was serious enough to require notifying Congressional leaders that Representative Jane Harman, Democrat of California, could become enmeshed in an investigation into Israeli influence in Washington, former government officials said Thursday. But Attorney General Alberto R. Gonzales told the director of the agency, Porter J. Goss, to hold off on briefing lawmakers about the conversation, between Ms. Harman and an Israeli intelligence operative, despite a longstanding government policy to inform Congressional leaders quickly whenever a member of Congress could be a target of a national security investigation. One reason Mr. Gonzales intervened, the former officials said, was to protect Ms. Harman because they saw her as a valuable administration ally in urging The New York Times not to publish an article about the National Security Agency's program of wiretapping without warrants. The accounts provided new details about tension between senior C.I.A. officials and the attorney general over what to make of the wiretapped conversations involving Ms. Harman, which the former government officials said first occurred in spring 2005. In the wiretapped conversation, Ms. Harman was overheard agreeing to a request made by an Israeli intelligence operative that she try to obtain leniency for two pro-Israel lobbyists in exchange for help in securing the chairmanship of the House Intelligence Committee, former officials said.