Vice President Dick Cheney disclosed Wednesday that he has the power to declassify sensitive government information, authority that could set up a criminal defense for his former chief of staff, I. Lewis "Scooter" Libby.

Cheney's disclosure comes a week after reports that Libby testified under oath he was authorized by superiors in 2003 to disclose highly sensitive prewar information to reporters. The information, about Iraq and alleged weapons of mass destruction, was used by the Bush administration to bolster its case for invading Iraq.

At the time of Libby's contacts with reporters in June and July 2003, the administration including Cheney, who was among the war's most ardent proponents, faced growing criticism. No weapons of mass destruction had been found in Iraq, and Bush supporters were anxious to show that the White House had relied on prewar intelligence projecting a strong threat from such weapons.

When Special Counsel Patrick Fitzgerald revealed Libby's assertions to a grand jury that he had been authorized by his superiors to spread sensitive information, the prosecutor did not specify which superiors.

But in an interview on FOX News Channel, Cheney said there is an executive order that gives the vice president, along with the president, the authority to declassify information.

"I have certainly advocated declassification. I have participated in declassification decisions," Cheney said. Asked for details, he said, "I don't want to get into that. There's an executive order that specifies who has classification authority, and obviously it focuses first and foremost on the president, but also includes the vice president."

Cheney added a ringing endorsement of Libby.

"Scooter is entitled to the presumption of innocence," said Cheney. "He is a great guy. I worked with him for a long time. I have tremendous regard for him. I may well be called as a witness at some point in the case, and it is therefore inappropriate for me to comment on any facet of the case."

Libby is not charged with leaking classified information, and Libby's lawyers said last week there was no truth to a published report that Libby's lawyers had advised the court or prosecutors that he will raise a defense based on authorization by superiors.

A legal expert said Cheney's TV appearance could nonetheless foreshadow a Libby defense.

Former Whitewater independent counsel Robert Ray said Cheney's ex-chief of staff could point to authorization from his superiors as part of his strategy at trial.

"If it turns out that Cheney was actively involved in decisions related to the disclosure of a CIA officer's identity and if the truth of it is that he was orchestrating the disclosure of information to the media, it seems to me that's a fundamentally different case than one centered around the activities of Libby," said Ray.

On Oct. 28 of last year, Libby was indicted on five counts of perjury, obstruction and lying to the FBI about how he learned of the identity of undercover CIA officer Valerie Plame and what he told reporters about it.

In July 2003, Plame's CIA identity was published by columnist Robert Novak eight days after Plame's husband, former U.S. Ambassador Joseph Wilson, accused the administration of twisting prewar intelligence to exaggerate the Iraqi threat. Wilson concluded that it was highly doubtful that a purported sale of uranium yellowcake by Niger to Iraq in the late 1990s had ever taken place.

A defense that Libby was authorized by superiors to leak sensitive data about Iraq would not appear to provide any help to the former Cheney aide for making false statements.

But some lawyers point out that setting up defenses before a jury involve more than simply constructing legal arguments.

"You're trying to present a persuasive case that your client should not be found guilty," said Ray, the former Whitewater prosecutor. "You're saying that even if my client did it, this is not a case that warrants conviction."

An authorization defense in the CIA leak case would mean that "much of what Libby was trying to do was aid and protect his boss Cheney," Ray suggested. The downside to employing such an approach is that it "almost comes with a defense that I did it."