WASHINGTON – Federal prosecutors said yesterday journalists have limited legal protection while a lawyer for two reporters who could go to jail for refusing to divulge their sources argued for a broader interpretation of the Constitution.

“There is a level of legal protection,” lawyer Floyd Abrams told a three judge panel of the U.S. Court of Appeals for the District of Columbia Circuit.

Mr. Abrams represents Time magazine’s Matthew Cooper and Judith Miller of the New York Times, who have been subpoenaed in the grand jury investigation into the leak of an undercover CIA officer’s name.

In October, the reporters were held in contempt by a federal judge for refusing to disclose their confidential sources. Both reporters face up to 18 months in jail pending the outcome of their appeal.

Assistant U.S. attorney James Fleissner argued that First Amendment protection exists for journalists, but only in a “very, very narrow” way. It applies, he argued, in cases where there has been intimidation or bad faith investigations – and not in the case of Ms. Miller and Mr. Cooper.

The special prosecutor in the case, U.S. Attorney Patrick Fitzgerald, is investigating whether a crime was committed when someone leaked the identity of CIA officer Valerie Plame. Her name was published in a 2003 column by Robert Novak, who cited two senior administration officials as his sources.

The column appeared after Ms. Plame’s husband, former Ambassador Joseph Wilson, wrote a newspaper opinion piece criticizing President Bush’s claim that Iraq had sought uranium in Niger. The CIA had asked Mr. Wilson to check out the uranium claim. Mr. Wilson has said he believes his wife’s name was leaked as retaliation for his critical comments.

Disclosure of an undercover intelligence officer’s identity can be a federal crime if prosecutors can show the leak was intentional and the person who released that information knew of the officer’s secret status.

Beyond the First Amendment, Mr. Abrams argued the court should rule there is a federal common law privilege based on the recognition of 49 states of legal protections for journalists.

One of the appeals court judges, David B. Sentelle, seemed especially skeptical of Mr. Abrams’s arguments. At one point, Mr. Sentelle said the grand jury would just shut down if the court were to agree to such a privilege for the press.

Mr. Sentelle also questioned the reach of such a privilege, asking if bloggers should be covered, too. He said anyone can set up a blog, or Internet journal, and wondered whether all bloggers are true journalists.

Prosecutors have interviewed President Bush, Vice President Cheney, Secretary of State Powell, and other current or former administration officials in the investigation. Journalists from NBC and The Washington Post also have been subpoenaed.

In August, Mr. Cooper agreed to provide limited testimony about a conversation he had with Lewis “Scooter” Libby, Mr. Cheney’s chief of staff, after Libby released Mr. Cooper from his promise of confidentiality.

Mr. Fitzgerald then issued a second, broader subpoena seeking the names of other sources.