GOP Leaders Urge Probe in Prisons Leak

"If you want to investigate everything and not be selective, that would make sense," he said.

Sen. Lindsey O. Graham (R-S.C.) said: "Talk about not seeing the forest for the trees. The real story is those jails."

More generally, Republicans suggested it is unwise to pick a fight with the media over an issue that exposes so many political vulnerabilities for their party.

The emergence of the congressional leaders' letter came as a surprise to House intelligence committee Chairman Peter Hoekstra (R-Mich.) and Senate intelligence committee Chairman Pat Roberts (R-Kan.), both of whom said they learned of the request from the media. Roberts said that his committee "stands ready to be of service" but that he had "not received any marching orders from the leadership."

The marching orders laid out by Frist and Hastert are detailed and are requested in urgent language. Those orders include verifying that the information supplied to The Post was accurate and classified, identifying who leaked the information and under what authority, and detailing "the actual and potential damage done to the national security of the United States and our partners in the Global War on Terrorism."

"The leaking of classified information by employees of the United States government appears to have increased in recent years, establishing a dangerous trend that, if not addressed swiftly and firmly, likely will worsen," the letter states.

White House spokesman Scott McClellan declined to say whether the president endorsed the probe, saying the decision belonged to the congressional leaders. But he did not offer any discouragement.

"The leaking of classified information is a serious matter and ought to be taken seriously," he told reporters.

Democratic leaders expressed their own concern about national security leaks, but in their case the emphasis was on the alleged release of Plame's name by indicted former White House aide I. Lewis "Scooter" Libby. Senate Minority Leader Harry M. Reid (Nev.), Pelosi and other Democrats sent two letters to Bush, urging him to declare publicly that he will not pardon Libby. Without such a declaration, Reid said, Libby will have no incentive to cooperate with Special Counsel Patrick J. Fitzgerald.

Staff writers Dan Eggen and Walter Pincus contributed to this report.