Washington ? Facing renewed controversy over allegations that it exposed a covert agent to punish a critic, the White House Monday rejected Democratic calls for a special prosecutor to probe the matter, saying the Justice Department could handle it fairly.

White House spokesman Scott McClellan also denied that chief political strategist Karl Rove played a role in the leak, saying Rove had personally assured him he was not involved. The individual who initially suggested that Rove was involved pulled back from the implication Monday, but asserted that Rove had “condoned” the leak.

McClellan said the White House would cooperate with a Justice Department investigation into the matter and that any staffer found to have revealed the identity of an undercover spy would be fired. “The president expects everyone in his administration to adhere to the highest standards of conduct,” he said.

But McClellan said federal investigators had not contacted any White House staffers and that the White House was doing nothing on its own to determine whether its people were involved. “If I chased every anonymous source in the media, I’d spend all my time doing that,” he said.

Acting on a CIA request, the Justice Department has opened a preliminary investigation into the identification of Valerie Plame, the wife of former diplomat Joseph Wilson, as an undercover CIA operative on weapons of mass destruction. Plame’s name and occupation were revealed in July by syndicated columnist Robert Novak, who said the information came from “two senior administration officials.” It is a federal crime to reveal the identity of a covert CIA agent.

Uranium report

Shortly before Novak’s column appeared, Wilson revealed that he had been asked by the CIA in 2002 to investigate reports that Iraq was seeking to buy enriched uranium in the West African country of Niger. Wilson reported that the allegation was baseless, yet it was included in President Bush’s 2003 State of the Union speech. In what turned out to be a major embarrassment, Bush was eventually forced to acknowledge he could not back up his statement.

The controversy over leaking was the latest Iraq-related problem for Bush, along with the administration’s failure to find Saddam Hussein or the weapons of mass destruction that Bush cited as justification for waging war in Iraq.

The leak erupted into a political controversy Monday when a host of Democrats demanded that the investigation be turned over to a special prosecutor. They said a Justice Department run by a Bush appointee had an inherent conflict of interest in investigating alleged wrongdoing by the White House. “We need the most independent, fearless investigation possible,” said Sen. Charles Schumer, D-N.Y. “Something as sensitive as this should not be done in a business-as-usual way or by a political appointee of the president.”

While saying he did not believe Bush was involved in the leak, Schumer strongly criticized the president for what he said was his failure to investigate it more aggressively. “He should be leading the charge,” Schumer said. “He should be furious, just as furious as if somebody betrayed our troops in Iraq.”

McClellan responded that if Schumer “has any information to suggest there was White House involvement, he should report that to the Department of Justice. We don’t have any information to suggest there was White House involvement.”

‘Fair game’

McClellan also rejected the calls for a special prosecutor, saying the inquiry was best left to “career professionals” who would handle it impartially. A Justice Department official confirmed that the preliminary inquiry was being conducted by career prosecutors and FBI agents.

McClellan said he had spoken directly to Rove after Wilson had publicly suggested that Rove was responsible for the leak and that Rove had categorically denied any involvement.

Wilson, in interviews Monday with several news organizations, pulled back from his original statement about Rove’s role, but insisted that the powerful strategist had at a minimum “condoned” the exposure of his wife.

Wilson said he believed that the leak took place in “two waves,” the first being the disclosure to Novak. He said that exactly one week after the Novak column appeared on July 14, he received a call from a reporter who told him “he had just gotten off the phone with Karl Rove and that Rove had said Wilson and his wife were fair game.”