ALEXANDRIA, Va. — A federal judge in the trial of two former lobbyists for the American Israel Public Affairs Committee said yesterday that a government proposal for keeping classified information out of the public record has “no precedent,” and he ordered open arguments on the matter.

Judge Thomas Ellis III confirmed that government lawyers suggested a “silent witness” procedure in which the trial participants and the jury would listen to classified evidence that journalists and the public would not be able to hear. He called the approach “fairly novel” but acknowledged that it raised serious constitutional questions that the court would have to resolve.

The judge ordered both sides to submit written briefs on the defense’s motion objecting to the government’s proposal, and he scheduled oral arguments — which will be open to the public — for a month from Friday.

The ruling comes amid an escalating dispute in the case over how secret evidence, including intercepted and wiretapped phone conversations, will be presented during the trial, which is scheduled to begin June 4 in U.S. District Court in Virginia. The defendants, Steven Rosen and Keith Weissman, were indicted in 2005 on charges that, as lobbyists for Aipac, they passed classified information to an Israeli official and to reporters, violating American espionage law.

A consortium of news organizations filed a motion on Tuesday to restrain any government attempt to present evidence that the public would not be able to see. Judge Ellis denied the motion at a hearing yesterday, but he went to great lengths to dismiss what he called a “hyperbolic” suggestion by the defense that the government was trying to “close the trial.”

“It isn’t a closed trial. It won’t be a closed trial,” the judge said.

With attorneys for the Reporters Committee for Freedom of the Press in the courtroom, he expressed disdain for the need for secrecy and said repeatedly he would try to keep as much of the proceedings open to the public as possible.

“I dislike under-seal matters,” Judge Ellis said. “They’re obnoxious to me. But the law requires it.”

Under provisions of the Classified Information Procedures Act, the court is considering what secret evidence will be admitted in the case and how it will be presented to the jury. Judge Ellis said that by law, those hearings have to be closed, and in ruling that the arguments over the government’s proposal for a “secret witness” procedure will be public, he instructed the defense to keep classified information out of its briefs.

Lawyers for both sides raised little objection to the judge’s instruction. In dismissing the motion by the press consortium, Judge Ellis told its lawyers they were free to resubmit it once he begins considering the arguments for and against the government’s “silent witness” proposal.

While the judge gave little indication as to whether he would approve the method, the defense may have the upper hand, according to recent history. “Most judges, maybe all judges, that have heard that proposal have rejected it,” a San Francisco-based attorney with experience in cases involving classified information, John Cline, said. Mr. Cline handled classified information for the defense of I. Lewis Libby, the former chief of staff to Vice President Cheney who was convicted last week of perjury and obstruction of justice.

The court will likely have to address several issues related to the proposal, including whether the jurors will be sworn to secrecy after hearing the secret evidence.

The executive director of the Reporters Committee, Lucy Dalglish, said she would give the judge “the benefit of the doubt” for now. “He clearly understands why the public has an interest in knowing what’s going on here,” she said. “We will continue to be vigilant in making sure the public is able to see as much of the proceedings as humanly possible.”