Prosecutors are recommending that a former White House aide convicted of perjury and obstruction of justice in March, I. Lewis Libby Jr. be sentenced to between 30 and 37 months in federal prison.

The special prosecutor handling the case, Patrick Fitzgerald, made the recommendation in a court filing that also contained a vigorous rebuttal of claims that his investigation into the leak of a CIA officer identity was too lengthy and unfairly pursued Libby after other sources for the disclosure were established.

Mr. Fitzgerald also made clear that one of the key parts of his inquiry was aimed at determining whether Vice President Cheney instructed Libby or other officials to disclose the identity of the CIA official, Valerie Plame also known by her married name, Valerie Wilson.

One reason the case had to be thoroughly investigated, the prosecutor said, was that “there was an indication from Mr. Libby himself that his disclosures to the press may have been personally sanctioned by the Vice President.” At several points, Mr. Fitzgerald’s filing also seems to express some skepticism about Libby’s descriptions of his contacts with Mr. Cheney.

Mr. Fitzgerald rejected suggestions that Libby is entitled to leniency because of his lengthy government service. “We would not be prepared to excuse those who served in the FBI, the CIA, the military or the Peace Corps if they were found to have perjured themselves and committed obstruction of justice during a criminal investigation of a national security matter. We should not apply a different set of rules to Mr. Libby because he served in the White House,” the prosecutor wrote.

For the first time, Mr. Fitzgerald today flatly rejected claims by Libby’s backers that Ms. Wilson was not considered a covert agent at the time her identity was exposed. The prosecutor said “it was clear from very early in the investigation” that she was covered by a federal law protecting such agents. The issue of whether Ms. Plame was covert or not was put off limits by the judge at Libby’s trial.

Mr. Fitzgerald said it would have improper to overlook Libby’s false statements simply because others were implicated in the first published leak about Ms. Plame.

“It is undisputed but of no moment that it was known early in the investigation
that two other persons (Richard Armitage and Karl Rove) in addition to Mr. Libby had
disclosed Ms. Wilson’s identity to reporters, and that Messrs. Armitage and Rove were the
sources for columnist Robert Novak’s July 14, 2003 column, which first publicly disclosed
Ms. Wilson’s CIA affiliation. The investigation was never limited to disclosure of Ms.
Wilson’s CIA affiliation to Mr. Novak,” Mr. Fitzgerald wrote. “Peremptorily closing this investigation in the face of the information available at its early stages would have been a dereliction of duty, and would have afforded Mr. Libby and others preferential treatment not accorded to ordinary persons implicated in criminal investigations.”

The prosecutor also rejected the notion that political concerns played a role in the pursuit of the case. “Mr. Libby’s prosecution was based not upon politics but upon his own conduct,” Mr. Fitzgerald wrote.

Mr. Fitzgerald portrayed Libby as someone who faced a stark choice about whether to be candid about his involvement and made the wrong decision.

“He, of course, could have told the truth, even if, as was the case for many other witnesses, doing so risked the possibility of criminal prosecution, or personal or political embarrassment. He also could have declined to speak to the FBI agents, invoked his Fifth Amendment rights before the grand jury, or challenged any lines of inquiry he believed improper,” Mr. Fitzgerald wrote. “Regrettably, Mr. Libby chose the one option that the law prohibited: he lied….Mr. Libby lied about nearly everything that mattered.”

Libby is scheduled to be sentenced by Judge Reggie Walton on June 5.

The defense’s position on sentencing is expected to be filed shortly.