The disbarred attorney Lynne Stewart next week will seek to have overturned her conviction of acting as middleman between a terrorist she represented and his followers in Egypt.

The Justice Department isn’t pleased with the outcome of the case, either: It will be arguing that Stewart’s sentence of 28 months, which prompted celebration among her supporters outside the courthouse in 2006, was much too lenient. Prosecutors are aiming for a sentence of several more decades.

Stewart’s case, along with those of two co-defendants, her translator and law clerk, will be argued Tuesday afternoon before the U.S. 2nd Circuit Court of Appeals. The panel of three judges hearing the case will review whether the convictions should stand, and, if so, whether the trial judge should give new, lengthier sentences.

Stewart has claimed that her prosecution represented an assault by the government on defense lawyers who were willing to represent unpopular clients. The case never became a rallying point among the legal community. Many lawyers, initially skeptical of the government’s case, later came to see the charges as justified as the seven-month trial unfolded in 2004 and 2005.

“There was really no consensus in the bar that the government was overplaying its hand,” an expert in human rights and international law, Scott Horton, who teaches at Columbia Law School, said. “I would say, in my own view, it came out right.”

Stewart was convicted after she smuggled out of prison a message from one of her clients, Sheik Omar Abdel Rahman, who was serving a life sentence for his role in a 1995 terrorist plot to blow up landmarks around New York City. The trial and appeals were concluded, but Stewart had taken to visiting Rahman in prison to boost his morale, she had said. In violation of a prison rule meant to prevent Rahman from contacting followers in Egypt, Stewart relayed a statement from the sheik to a reporter in Cairo. In the message, Stewart said the sheik was withdrawing his support from a ceasefire that his followers in a terrorist organization, the Islamic Group, were then honoring with the government of Egypt. Prosecutors never linked the sheik’s message with any specific act of violence.

In addition to Stewart, her translator during conversations with Rahman, Mohamed Yousry, and her paralegal, Ahmed Abdel Sattar, were convicted. Sattar was sentenced to 24 years in prison, a sentence that reflected not just his involvement with Rahman but also his issuance of a fatwa encouraging Muslims around the world to kill Jews.

The three appeals will be heard by judges John Walker, Guido Calabresi, and Robert Sack of the 2nd Circuit.

Perhaps the most significant event, as far as the case is concerned, to occur since Stewart was sentenced in October 2006 was a pair of U.S. Supreme Court decisions issued last year that give judges more leeway in deciding the reasonableness of sentences. Those decisions may undercut the prosecution’s argument that the sentences issued by the trial judge, John Koeltl, were unreasonable because they were so lenient compared to the range of possible sentences.

“The Supreme Court’s recent decisions are likely to make the 2nd Circuit more comfortable in affirming Stewart’s sentence even though it varied widely from what federal sentencing guidelines recommended,” a criminal defense lawyer who teaches sentencing law at the Benjamin N. Cardozo Law School, Harlan Protass, said. A phone message left at Stewart’s defense committee was not returned.

Her supporters are meeting the night before the hearing at St. Mary’s Church on 126th Street.