A lawyer for Minnesota's two largest newspapers told the Supreme Court Wednesday the Constitution's free-press guarantees shield publications from being sued when they break promises and reveal the identity of a confidential source.

Some justices voiced doubts about such sweeping protection.And a lawyer for the source who sued accused the newspapers of trying to place themselves above the law.

The attorney for the Star Tribune of Minneapolis and the Saint Paul Pioneer Press, John French, said "the core function" of a newspaper is "revealing truthful information" and it should not be penalized for doing that job even if a source is betrayed.

"It's part of the editorial judgment" to determine whether a source's identity should be disclosed, he said.

Justice Anthony M. Kennedy said French was suggesting that newspaper editors should be granted such protection, but not reporters or their sources.

"It's an odd calculus that those closest to the source of the truth" are left unprotected, Kennedy said.

Elliot Rothenberg, a lawyer for the source who sued the Minnesota newspapers, said "a solemn promise was made" to his client, and "it was not kept."

Noting that news organizations normally defend the need for such confidentiality, Rothenberg accused the newspapers of trying to place themselves above the law.

The Minnesota newspapers are asking the justices not to reinstate a $200,000 award won by a news source whose name was disclosed.

The court is expected to announce a ruling by July.