Journalist Judith Miller, who was recently jailed for refusing to reveal confidential sources to prosecutors, has urged U.S. senators to support a proposal to shield reporters in similar situations.

Ms. Miller, of The New York Times, told a Senate panel Wednesday a proposed law that would severely restrict judge's ability to jail reporters in such situations is needed to protect press freedom.

The Justice Department opposes the legislation, saying it could hamper its ability to fight crime.

Ms. Miller spent 85 days in jail for refusing to reveal sources to prosecutors investigating whether White House officials broke the law by leaking the identity of CIA agent Valerie Plame to journalists.

Ms. Plame's husband, diplomat Joseph Wilson, said the naming of his wife in a 2003 newspaper column was White House payback for his criticism of the U.S.-led war in Iraq.

The White House has not commented on Mr. Wilson's allegations.