"Why? Disarray. That's part of it, " he said. "The NSC has been gutted, and people are just trying to keep their jobs."

The sources said that White House officials had informed the foreign affairs panel that the FBI, investigating potential crimes, had taken control of some documents. Furthermore, the White House has refused to accept committee letters to Poindexter and North. "They said they don't work there anymore, " a source said.

House Foreign Affairs Committee staffers said that discussions with McFarlane and his lawyers have indicated that the former national security adviser has agreed to testify "openly and frankly" Monday about the rationale that guided his involvement in the development of the Iran arms policy.

McFarlane spoke publicly last month before the Gaithersburg (Md.) Chamber of Commerce on the Iran dealings. The sources said they expected that McFarlane would, nonetheless, request that the hearings be closed when questioning begins to touch sensitive national security questions.

Other sources doubted that McFarlane would appear.

The committee sources said they doubted that Poindexter, who invoked the Fifth Amendment before the Senate Intelligence Committee last week, would consent to testify or, perhaps, even show up. If he appears, he might have to invoke the Fifth Amendment on national television Tuesday.

CNN and PBS are to broadcast the hearings live, and the three major networks have requested the necessary House permits to allow live coverage.

Monday's hearings will intensify congressional inquiry into the scandal, and the widening number of panels involved suggests that despite attempts to keep the inquiries simple, the process is likely to bewilder the American public.

Parallel to the House Foreign Affairs Committee, the Senate Select Intelligence Committee is to continue closed hearings, reportedly with testimony from Rob Owen, a private aide to North who maintained close contacts with Nicaraguan rebels when U.S. law prohibited direct American support.

The House Intelligence Committee also will begin hearing testimony from CIA officials Tuesday.

After this week's testimony, the panels will probably adjourn for Christmas. In early January, special investigative committees are to be officially convened in both houses. Administration officials are likely to be appearing simultaneously before both panels.