WASHINGTON — The defense at the trial of I. Lewis Libby Jr. rested its case yesterday after the judge and attorneys sparred over the legal impact of the former White House aide’s decision not to take the witness stand.

At a midday session out of earshot of the jury, Judge Reggie Walton seemed to complain that Mr. Libby’s lawyers had duped the court and the prosecution by indicating, during months of closed-door court hearings on classified information issues, that the defendant would testify.

The conflict came to a head as the defense insisted that prosecutors should be held to an agreement that the jury would be given a set of agreed facts about Mr. Libby’s mind-set and matters that preoccupied him during a time period in 2003 and 2004 when the defense says the White House aide may have forgotten conversations he had about a CIA officer whose identity was leaked to the press.

“I just don’t buy that, counsel,” Judge Walton said to a defense attorney, John Cline. “I don’t think you can play coy by suggesting Mr. Libby is going to testify” and then hold the government to the deal, the judge said, raising his voice for one of the few times during the month-long trial. “It was absolutely understood from everything that was said to me that Mr. Libby was going to testify.”

Judge Walton said he respected Mr. Libby’s constitutional right to remain silent, but said defense lawyers should not be able to use the pretrial process for handling classified information to force disclosures based on a particular defense and then use that information in a different way. “It’s too much of a game now. This is supposed to be about finding the truth,” the judge said. “I won’t permit it.”

Judge Walton said he was confident higher courts would agree with him. “If I get reversed on that one, maybe I need to hang up my spurs,” he said.

Returning to the bench later in the day, Judge Walton noted that his sharp comments prompted the Associated Press to move a story saying he claimed he was “misled” by the defense team. “I never said that,” the judge insisted, adding that he accepted the defense’s representations that it recently changed its mind after planning in good faith to put Mr. Libby on the stand. Judge Walton asked reporters to correct their stories, but he did not explain his earlier suggestions that the defense had been “coy” or was playing games.

Mr. Libby’s chief trial counsel, Theodore Wells Jr., sought to clear the air by telling the court that the defense’s intention to put Mr. Libby on the stand began to waver in December after the government turned over evidence that could undermine the testimony of some prosecution witnesses. One such disclosure was the grant of immunity to a former White House press secretary, Ari Fleischer, who testified for the prosecution.

“The canvas and the landscape radically changed” after the defense learned more about the government witnesses, Mr. Wells said. Hesaid the decision not to have Mr. Libby testify was a tactical one made because the defense believes the prosecution’s evidence does not prove beyond a reasonable doubt that Mr. Libby intentionally lied to investigators and a grand jury investigating how the press learned the identity of the CIA operative, Valerie Plame.

“There’s no box on the verdict sheet that says ‘innocent’ or ‘you didn’t tell the whole story.’ The box says ‘guilty’ or ‘not guilty,'” Mr. Wells observed.

The jury, which is expected to hear closing arguments on Tuesday, prompted loud laughter as it entered. In honor of Valentine’s Day, all but one of the jurors were clad in identical red T-shirts.

The jury listened as Mr. Cline read a lengthy list of international crises and terrorist threats covered in Mr. Libby’s CIA briefings.

Jurors also heard that an FBI report from early in the probe shows that a key prosecution witness, Timothy Russert of NBC News, initially said that he “could not completely rule out the possibility” that he discussed Ms. Plame with Mr. Libby. Mr. Libby claims Mr. Russert told him about Ms. Plame, but the “Meet the Press” host testified to the grand jury and at the trial that he was certain that such an exchange never took place.

Judge Walton yesterday rejected two defense attempts to impugn Mr. Russert’s credibility. While being cross-examined last week about concessions the government made to gain his testimony, Mr. Russert, who has a law degree, denied knowing that grand jury witnesses are not allowed to have attorneys with them in the grand jury room. The defense subsequently found four television appearances in which the NBC bureau chief talks about that specific aspect of the grand jury process in connection with investigations of President Clinton.

Mr. Wells asked to show the jury the videos, but a prosecutor, Debra Bonamici, said the statements were nine years old and that Mr. Russert may have been parroting information fed to him by his staff.

After seeming inclined to admit the videos, Judge Walton nixed them. “It’s a totally, wholly collateral matter,” he said.

Mr. Wells also asked to present evidence that prosecutors agreed that Mr. Russert could challenge a grand jury subpoena despite the possibility that he waived his right to do so by speaking to an FBI agent about the leak under investigation. “He went around the country telling people he was this great protector of the First Amendment,” when in fact he had cooperated with the probe, Mr. Wells said. “It was totally kept out of the public record and Mr. Russert took great advantage of that.”