Former vice presidential aide Lewis Libby pleaded not guilty Thursday to criminal charges related to the leaking of a covert CIA officer's name two years ago.

Mr. Libby is recovering from a foot injury and hobbled into federal court in Washington on crutches to enter a plea of not guilty to all five of the criminal charges he faces.

Last week, a federal grand jury indicted Mr. Libby on charges of perjury, making false statements and obstruction of justice in connection with a nearly two-year old investigation into who leaked the identity of covert CIA officer Valerie Plame.

Ms. Plame is married to former ambassador Joseph Wilson, who became a critic of the intelligence used by the Bush administration to justify the U.S. led invasion of Iraq. Mr. Wilson has accused top White House officials of leaking his wife's name as part of a campaign of political retaliation, a charge Bush officials deny.

Following Mr. Libby's court appearance Thursday, his lawyer, Ted Wells, made a brief statement to reporters. "In pleading not guilty, he has declared to the world that he is innocent," stated Mr. Wells. "He has declared that he intends to fight the charges in the indictment and he has declared that he wants to clear his good name and he wants a jury trial."

Special Prosecutor Patrick Fitzgerald says Mr. Libby lied to a grand jury and investigators about conversations he had with journalists concerning Valerie Plame. Mr. Libby testified he learned about her identity from journalists. Prosecutor Fitzgerald says Mr. Libby was told about Ms. Plame by government officials, including Vice President Dick Cheney.

Divulging the identity of a covert CIA officer under certain circumstances is a violation of law.

Opposition Democrats have seized on the Libby indictment to call for more scrutiny of how the Bush administration may have twisted intelligence to win public support for the ouster of Iraqi leader Saddam Hussein.

Democrats are also calling on Vice President Cheney to replace any aides who may have been involved in discussions about Valerie Plame.

"You would think that in the face of this disclosure and the indictment of the vice president's chief of staff, we would see a new approach for this administration," said Senate Democratic party leader Harry Reid of Nevada. "But here they go again. The vice president refuses to answer any questions. He refuses to bring in a new team [of aides]. He refuses to apologize and admit his people did anything wrong."

Prosecutor Fitzgerald said Vice President Cheney did nothing wrong in discussing Valerie Plame's CIA status with other government officials.

The vice president is among several administration officials who could be called to testify in Lewis Libby's trial. That, in turn, could refocus attention on how Mr. Cheney and others in the administration shaped intelligence on Iraq to build public support for the U.S. led invasion.

Congressional Republicans are already warning Democrats not to try to put Vice President Cheney on trial as part of the case against Mr. Libby.

"I think there will be some who will try to do that and I think they will fail miserably," said Senator Trent Lott, Republican from Mississippi, who spoke on Fox News Sunday. "Vice President Cheney is, I think, the most outstanding vice president we have ever had. He had every right to know some of these things."

Lewis Libby's next court date has been set for February, but there is no word yet on when a trial would begin.

Meanwhile, President Bush's top political aide, Karl Rove, also talked to reporters about Valerie Plame and remains under investigation.