In a case that could further define what constitutes protected speech for lawmakers, government attorneys argued in federal appeals court on Tuesday that Rep. John Murtha (D-Pa.) is immune from a libel lawsuit over his comments about a 2005 incident in Haditha, Iraq.

The Justice Department, which is representing Murtha, is seeking to overturn a September 2007 order by the U.S. District Court for the District of Columbia permitting the senior Democrat to be deposed along with limited discovery of evidence.

Marine Staff Sgt. Frank Wuterich filed suit against Murtha in August 2006 for libel, defamation and invasion of privacy, alleging the Democrat “publicly and falsely accused” the Marines of “cold-blooded murder and war crimes” in the deaths of two-dozen Iraqis without facts to support that claim.

The U.S. Court of Appeals for the D.C. Circuit did not issue an immediate verdict Tuesday.

The three-judge panel vigorously questioned both sides, however, at times offering potentially key criticisms of both the government strategy as well as Wuterich’s basic premise.

Both Circuit Judge Karen LeCraft Henderson and Senior Circuit Judge Harry Edwards echoed arguments made by Wuterich attorney Mark Zaid, who questioned whether the appeals court has jurisdiction in the case.

Zaid asserted that because the District Court did not reject a government motion to dismiss the case, but instead put the motion “in abeyance” pending the outcome of the discovery, the case is not ripe for the appellate court.

“The District Court did nothing but enter a discovery order,” Henderson said.

But Assistant U.S. Attorney Darrell Valdez argued that the court must rule on the issue before Murtha is deposed.

“Once [deposition] has occurred, his absolute immunity is gone,” Valdez said. The government asserts that Murtha acted within the “scope of his employment” when he discussed the Haditha incident and is therefore protected under the Westfall Act, which guards federal employees from such prosecution. Instead, the government has moved to substitute the United States as the defendant in the case, effectively rendering it moot.

But Zaid argued that unlike similar Westfall Act cases — such as the ultimately unsuccessful lawsuit filed against then-Rep. Cass Ballenger (R-N.C.) by the Council on American-Islamic Relations for disparaging remarks he made in a 2003 interview — Murtha did not give one interview, but repeated the remarks over a period of several weeks.

In addition, Zaid argued that other Members, including Rep. John Kline (R-Minn.), issued retractions after making similar statements, suggesting Murtha understood such comments were inappropriate.

But Edwards, the senior judge, suggested that Wuterich’s case could face a serious hurdle, stating that the Marine’s argument falls short.

“I read it and I said there’s nothing here. … The complaint doesn’t do it,” Edwards said. He later added that arguments for the deposition appeared questionable, even suggesting a witch hunt: “You can’t come in and say, ‘I’m kind of wondering what was going on.’”

Edwards also cast a skeptical eye on Wuterich’s assertions that Murtha’s statements were intended to embarrass then-Secretary of Defense Donald Rumsfeld, and therefore were made for the Pennsylvanian’s personal gain rather than professional purposes.

“That’s what Congresspeople do. … Your best assertions, as I’m hearing them, don’t satisfy even the most generous pleading requirements,” Edwards added.

Zaid acknowledged that “at the end of the day, it may very well be the case Congressman Murtha was acting in the scope of his employment,” but asserted that deposition is still necessary to make that determination.

Following the hearing, Zaid suggested that the court could opt to remand the case back to the District Court.

“The easiest way is going to be jurisdiction,” Zaid suggested. “The lines haven’t been drawn yet, but you can see a faint outline of where they are.”

In the meantime, Wuterich has pleaded not guilty in a military court to voluntary manslaughter in the Haditha incident. That case remains on hold, pending the outcome of an appeals case in which the government has sued CBS to obtain outtake footage of an interview with Wuterich that originally aired on “60 Minutes” in early 2007.

A second Marine, Lance Cpl. Justin Sharratt, filed a similar suit against Murtha in the U.S. District Court for the Western District of Pennsylvania in September alleging slander, defamation and invasion of privacy, as well as a violation of his constitutional right to due process and a fair trial. Sharratt has been cleared of any wrongdoing in the Haditha incident.