A frenzy of anticipation is gripping politicians and pundits in the nation’s capital as top White House aides await word from a special prosecutor about whether they will be indicted in connection with the leak of the identity of a CIA operative.

With the grand jury investigating the episode set to expire on Friday, the prosecutor, Patrick Fitzgerald of Chicago, is expected to announce the outcome of his probe this week. According to witnesses and lawyers involved in the case, Mr. Fitzgerald appears to be focusing on two White House officials, Karl Rove and I. Lewis Libby, and the roles they may have played in the unmasking of the CIA employee, Valerie Plame, in the press in 2003.

Mr. Fitzgerald’s inquiries about alleged discrepancies in the accounts of the White House officials who have testified in the probe have led some attorneys to conclude that the veteran prosecutor is considering bringing perjury or obstruction-of-justice charges.

Some Republicans appeared to be making a last-minute effort yesterday to persuade the prosecutor to drop the case if he cannot bring an indictment that relates directly to the alleged leak.

“I certainly hope that if there is going to be an indictment that says something happened, that it is an indictment on a crime and not some perjury technicality where they couldn’t indict on the crime and so they go to something just to show their two years of investigation was not a waste of time and taxpayer dollars,” Senator Hutchison of Texas said on NBC’s “Meet the Press.”

Mrs. Hutchison compared the CIA leak case to the prosecution of homemaking guru Martha Stewart, who was convicted last year of conspiracy, perjury, and obstruction of justice in an insider trading investigation but was never charged with violating securities laws. “I also think we are seeing grand juries and U.S. attorneys and district attorneys that go for technicalities, sort of a gotcha mentality in this country,” the senator said.

Senator Schumer, a Democrat of New York, praised Mr. Fitzgerald as “above reproach” and promised to accept whatever decision the prosecutor makes. “Because Patrick Fitzgerald is a prosecutor’s prosecutor, and we should abide by that,” Mr. Schumer said on NBC.

However, the chairman of the Democratic Party, Howard Dean, said he would not pledge to drop the issue if Mr. Fitzgerald decides no prosecution is warranted. “I fundamentally don’t think these are honest people running the government,” Dr. Dean told ABC’s “This Week.”

Through his attorney, Mr. Rove, who is a deputy chief of staff and Mr. Bush’s chief political adviser, has repeatedly denied wrongdoing. The lawyer for Mr. Libby, who is chief of staff to Vice President Cheney, has refused all comment in recent days.

Attorneys who have worked with Mr. Fitzgerald said they expect the intensifying maelstrom of criticism and public second-guessing to have no impact at all on whether he decides to press forward for indictments in the politically sensitive case. “He is not going to be the slightest bit affected one way or the other by what anybody else thinks,” said Andrew McCarthy, who prosecuted terrorism cases with Mr. Fitzgerald in New York. “He is utterly apolitical. I lived with the guy for a long time. He feels strongly about things. He just doesn’t feel strongly about politics.”

Mr. McCarthy said Mr. Fitzgerald’s lack of concern for politics was apparent in his aggressive tactics, such as a decision to seek jail for a New York Times reporter who refused to testify in the inquiry, Judith Miller. “He’s managed at one stage or another to” anger everyone, Mr. McCarthy said.

The investigation stems from allegations that Bush administration officials deliberately outed Ms. Plame as a CIA employee after her husband, Joseph Wilson, criticized the president’s policies toward Iraq. A July 2003 newspaper column by Robert Novak identified Ms. Plame as “an Agency operative” and reported that two administration officials suggested that her husband be sent to Africa to investigate claims that Saddam was seeking nuclear materials there.

In December 2003, after the then attorney general, John Ashcroft, recused himself from the matter, Justice Department officials in Washington asked Mr. Fitzgerald to lead the inquiry into the leak.

While some Democrats, such as Rep. Jerrold Nadler, are now pressing to expand the probe into a wide-ranging examination of the Bush administration’s public statements during the run-up to the invasion of Iraq, a few voices are warning that even as it is currently focused the leak investigation could hamstring the public’s ability to hear informed debate about sensitive national security matters.

“If you have too much classified information and prosecutors decide who in the community gets prosecuted, it’s too much discretion. I’m not talking about obstruction. I’m not talking about perjury. I’m talking about making leaks into crimes,” a prominent criminal defense attorney in Washington, Abbe Lowell, told “Fox News Sunday.” “It can be very chilling to the media, and journalists and the American population ought to pay close attention,” said the attorney, who is representing a client, Steven Rosen, facing criminal leak charges in an investigation into pro-Israel lobbying.

Some of the fears about Mr. Fitzgerald’s probe relate to the possibility he might bring charges under a 1917 law against the disclosure of information about the national defense, or a more mundane statute prohibiting theft or conversion of government records.

The editor of an online magazine, Slate, wrote last week that a successful prosecution of Mr. Rove or Mr. Libby under those laws “would turn the current chill into permafrost.” The editor, Jacob Weisberg, called Democrats’ jubilation over possible charges against Mr. Rove “unthinking and ultimately self-destructive.”