NEW YORK — In a case that civil libertarians say will have a chilling effect on lawyers representing unpopular clients, a jury has convicted civil rights attorney Lynne Stewart of conspiring to aid terrorists and lying to the government. Stewart, 65, faces up to 30 years in prison under the conviction, stemming from her representation of Egyptian Sheik Omar Abdel Rahman in a 1995 terrorism trial. Her co-defendants, paralegal Ahmed Abdel Sattar and interpreter Mohammed Yousry, were also convicted. Sattar faces life in prison and Yousry faces 20 years.

Stewart was charged based on special restrictions imposed on her and her client. In order to visit him in jail, Stewart had to swear that she would communicate with Abdel Rahman only about legal matters and she was forbidden to convey any messages to third parties, including the media. The prosecution won a conviction using wiretaps of phone conversations and videotapes of Stewart’s confidential prison conversations with her client. That was possible only because of post-9/11 rules issued by then-Attorney General John Ashcroft. Ashcroft decreed that the Justice Department could violate attorney-client privilege by eavesdropping on conversations between prisoners and their lawyers, if the attorney general believed those conversations were being used to “further facilitate acts of violence or terrorism.”

The jury found that Stewart had violated the restrictions imposed upon her by giving the news media information about her client’s views. Based on the tapes, the jury found that Stewart had made gibberish comments to prevent officials from listening in on her conversations with her client and the interpreter.

National Lawyer’s Guild President Michael Avery said Stewart’s actions “should have been viewed as protected by constitutional principles, including the Sixth Amendment right of her client to counsel and the First Amendment right of freedom of speech.”

Before 9/11, constitutionally protected conversations between lawyer and client would not have been admissible as evidence. In fact, the act of taping the conversations would have been illegal.

During Stewart’s trial, the prosecution played an Al Jazeera video of Osama bin Laden saying that he would “spill blood in the fields of jihad” unless Abdel Rahman was freed. Observers noted that the video had nothing to do with Stewart’s case, but was used to tie bin Laden’s name to Stewart.

“When you put Osama bin Laden in a courtroom and ask the jury to ignore it, that’s asking a lot,” said Stewart after the guilty verdict was announced Feb. 10.

The jury appeared to have been deeply divided. Two jurors asked to speak privately with the judge, and were said to have favored acquittal. While the verdict was read, one juror held her hand to her face, while another cried.

Ashcroft personally announced Stewart’s indictment in April 2002. It was the first time that the federal government had prosecuted a defense attorney in a terrorism case. Other lawyers who have made public information from defendants under similar restrictions have never been prosecuted.

“The U.S. Department of Justice was resolute from day one in making a symbol out of Lynne Stewart in support of its campaign to deny people charged with crimes of effective legal representation,” said Avery.

The guilty verdict was hailed by Ashcroft’s successor, Alberto Gonzales, who said the convictions “send a clear, unmistakable message.” Lawyers around the country fear the government’s aim is to discourage them from representing controversial clients.

“The government is hoping that lawyers will now think twice before representing clients with unpopular views or related to unpopular causes,” the National Lawyers Guild said.

Andrew Napolitano, a former judge of the Superior Court of New Jersey, now a Fox News analyst, called the Stewart conviction “a travesty.” In a Feb. 17 New York Times commentary, Napolitano said Stewart “faces up to 30 years in prison for speaking gibberish to her client and the truth to the press. It is devastating for lawyers and for any American who may ever need a lawyer. Shouldn’t the Justice Department be defending our constitutional freedoms rather than assaulting them?”

Michael Tigar, Stewart’s defense attorney, said she would appeal as far as she had to in order to get the conviction overturned.

Susan Webb contributed to this article.