Dick Cheney’s former chief of staff, Lewis “Scooter” Libby, was convicted yesterday of perjury, thrusting fresh allegations of corruption and the twisting of prewar intelligence into the heart of the Vice-President’s office.

Libby was found guilty on four counts of lying to FBI agents and to a grand jury, and obstructing justice over the leak of a CIA official’s identity whose husband was a prominent war critic.

He faces a possible 25 years in prison — though he is likely to get no more than two — and the disgrace of being the highest-ranking White House official convicted of a crime in more than a decade.

The verdict is likely to increase suspicions among a growing number of Americans that the US was misled over Iraq.

A spokesman for the jury said last night that he and his cojurors believed Libby had been sacrificed by his superiors, and pointed the finger at more senior White House officials, including Karl Rove, Mr Bush’s chief adviser.

Denis Collins said: “We had sympathy for Libby, he was the fall guy. Where was Rove, where were the others? Some jurors said, ‘This sucks, we wish we weren’t judging Libby’.”

Libby’s trial offered Washington some of the best courtroom political drama in recent times. It cast a harsh spotlight on Mr Cheney’s office, particularly his obsession with rebutting accusations that he had exaggerated the threat from Saddam Hussein to justify the invasion.

Democrats seized on the verdict, at a time when President Bush’s ratings are at record lows and two thirds of Americans oppose a war whose rationale was Iraq’s nonexistent weapons of mass destruction.

“It’s about time someone in the Bush Administration has been held accountable for the campaign to manipulate intelligence and discredit war critics,” Harry Reid, the Democratic Senate Leader, said.

Nancy Pelosi, the House Speaker, said: “The trial provided a troubling picture of the inner workings of the Bush Administration. The testimony unmistakenly revealed . . . a disposition to smear critics of the war in Iraq.”

The CIA official at the heart of the case, Valerie Plame, is married to Joseph Wilson, who in 2003 claimed that the White House made false prewar claims that Iraq had sought to buy uranium from Niger. Soon after, Ms Plame’s name was leaked to the press.

Libby was not charged with the crime of leaking a CIA operative’s identity but instead with lying about his role in how Ms Plame’s name was given to reporters. He said that he first heard about Ms Plame, and her CIA job, from journalists. But what the trial exposed was that as soon as Mr Wilson made his claims, Mr Cheney pursued an effort to discredit him with an obsessive ruthlessness.

He discussed Mr Wilson several times a day with Libby, and was the first to tell his top aide that Mr Wilson’s wife worked at the CIA.

Mr Cheney was determined to prove that Mr Wilson had been sent to Niger by his wife and not, as Mr Wilson claimed, by the Vice-President’s office.

In evidence, it emerged that the article in which Mr Wilson made his accusations was cut out by Mr Cheney and affixed to his desk, hand-written notes scrawled above it. It was Mr Cheney who told Libby to leak sensitive documents to reporters to discredit Mr Wilson.

Although there is no evidence that Mr Cheney believed the Administration’s claims about Saddam’s illicit weapons were false, the trial has made clear that Libby lied in order to hide that his boss had led a relentless campaign to rebut and discredit Mr Wilson.

Soon after the verdicts, Mr Collins, a spokesman for the jury, emerged to accuse other White House officials, including Mr Rove, of being complicit in Libby’s fall from grace. Mr Rove also talked to reporters about Ms Plame but was never charged. Mr Cheney gave no evidence at the trial.

“I am very disappointed with the verdict,” Mr Cheney said last night. “Scooter served our nation tirelessly and with great distinction through many years of public service.”

No sooner were the verdicts announced than many wondered if Mr Bush would use his presidential powers to pardon Libby, whose lawyers launched an immediate appeal.

The players

Joseph Wilson, 57

Former ambassador married to Valerie Plame. Sent to Niger to investigate claims that Iraq tried to buy uranium there. Accused White House in 2003 of using the Iraq-Niger link to bolster the case for war, even though, he says, he had discredited the claim

Valerie Plame, 43

Former CIA agent. Her name appeared in the press soon after her husband’s accusations against the Administration. The couple claimed the White House was deliberately “outing” her to punish and intimidate Mr Wilson

Lewis “Scooter” Libby, 56

Dick Cheney’s chief of staff and a neocon ideologue. Convicted of lying about his role in how Ms Plame’s name was given to reporters

Patrick Fitzgerald, 45

Special prosecutor appointed to investigate leak. Never charged any official with deliberately exposing Ms Plame. But proved Mr Libby was involved in a campaign to discredit Mr Wilson and then lied about it

Dick Cheney, 66

The most powerful vice-president in history. At the heart of the campaign to rebut Mr Wilson’s allegations

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