By Molly K. Hooper, CQ Staff

Rep. Dennis J. Kucinich may have to hold his tongue when he argues in favor of impeaching President Bush on Friday morning.

The Ohio Democrat, like every other witness scheduled to testify before the Judiciary Committee, has been put on notice by the committee’s Democratic staff.

The basic warning: No matter what they think about the information given to Congress and the American people before the Iraq War, under no circumstances are those testifying to call Bush a liar.

The staff made sure every witness had the Jefferson’s Manual page that says “personal abuse, innuendo, or ridicule of the President is not permitted. . . . Any suggestion of mendacity is out of order.”

And being called out of order could result in being unable to speak for the rest of the hearing — which would ruin the occasion for White House critics like Kucinich, who have been waiting a long time to air their grievances in a formal setting.

Judiciary Chairman John Conyers Jr. , D-Mich., said his staff tried to make sure the witnesses understand that “it’s not what you say, it’s the way that you say it.”

Democrats want the hearing to run smoothly without too much parliamentary disruption because committee Republicans intend to be vigilant in making sure that witnesses stay in line.

“They know we’re watching them. They are smart to realize they can’t violate House rules,” a senior Republican on the committee said.

The witnesses, in addition to Kucinich, are to include Reps. Maurice D. Hinchey , D-N.Y.; Walter B. Jones , R-N.C.; and Brad Miller , D-N.C.; former Rep. Bob Barr, R-Ga. (1995-2003), who now is running for president as a Libertarian; former Rep. Elizabeth Holtzman, D-N.Y. (1973-81); and several law professors.

The potential for violations of decorum extend well beyond accusations of untruthfulness. The witness list includes Vincent Bugliosi, author of “The Prosecution of George W. Bush for Murder.”