The White House is defending a statement that President Bush issued last month asserting that U.S. postal authorities have the right to open private mail without a warrant in what are considered emergency circumstances.
Mr. Bush issued the statement without fanfare when he signed a postal reform bill December 20.
The White House and the Postal Service contend his statement was meant to clarify present law, and that it does not represent new policy. But some lawmakers say it is an attempt by the president to expand his authority.
The bill's sponsor, Maine Senator Susan Collins of the president's Republican party, questioned the president's action.
Postal workers have authority to open mail without a warrant in very narrow circumstances - when they have credible evidence that the letter or package contains an explosive or other hazardous material. But in most cases, a judge must grant permission before government authorities can search private mail.
The New York Daily News first brought attention to Mr. Bush's action in a newspaper article Thursday.
Previously, the Bush administration generated controversy over a program that allows U.S. intelligence officials to eavesdrop without a warrant on telephone calls and e-mail between people in the United States and people overseas. Federal courts later ruled that the wiretapping is not legal unless Congress authorizes it.