President Bush said late Tuesday that he will oppose any congressional efforts to subpoena White House staff in the investigation of the firing of eight federal prosecutors, a scandal that has put his administration and Attorney General Alberto Gonzales under scrutiny in the last week.

"We will not go along with a partisan fishing expedition," Bush said. "I have proposed a reasonable way to avoid an impasse. I hope they (members of Congress) don't choose confrontation."

Bush said he has given Gonzales, White House political strategist Karl Rove and former counsel Harriet Miers the go-ahead to talk to congressional committees — but not under oath — in the investigation of the firing of the eight U.S. attorneys.

Bush said they are free to speak with lawmakers and their aides to explain how the decisions to oust the prosecutors were made.

"In this case, I recognize the importance of Congress understanding how and why this decision was made," Bush said in an evening press conference. "So I'll allow members of Congress to interview key members of my staff."

Sen. Chuck Schumer, D-N.Y., who is helping lead the Senate-side investigation, was quick to fire back Tuesday.

Though he said he was happy to hear that Bush wanted to cooperate so that the truth about why the attorneys were fired comes out, he felt the president's offer on how to participate in the probe was sorely lacking.

"When we learned what he has proposed, it can only be called very disappointing," Schumer told the Senate floor. "When you look at it closely, the cooperation is minimal ... The offer made by the president is not going to get the truth."

Without a public hearing, record of testimony in the form of a transcript or a statement made under oath, Schumer argued, nothing will be accomplished and nothing can be done to "restore the integrity of the Justice Department."

"Bottom line is, if the president wants the truth to come out, then he would have testimony given in a far more full and open way," Schumer said.

Earlier in the day, White House Counsel Fred Fielding met with House Judiciary Committee Chairman John Conyers and Senate Judiciary Committee Chairman Patrick Leahy to offer up Rove and Miers, but in a formal letter placed conditions on their appearances.

Fielding said the interviews would be limited to questions on communications between White House and Justice Department officials who may have discussed the request for resignations and communications between the White House and members of Congress about those requests.

"Those interviews should be conducted by both committees jointly," Fielding wrote.

"Questioning of White House officials would be conducted by a member or limited number of members, who would be accompanied by committee staff," the letter continues.

"Such interviews would be private and conducted without the need for an oath, transcript, subsequent testimony, or the subsequent issuance of subpoenas. A representative of the Office of the Counsel to the President would attend these interviews and personal counsel to the invited officials may be present at their election."

Click here to read Fielding's letter to lawmakers.

Fielding's offer "is sort of giving us the opportunity to talk to them but not giving us the opportunity to figure out what really happened here," Schumer told reporters earlier Tuesday, before his statements on the Senate floor.

He told the press that he and Conyers had been considering writing up subpoenas for Rove and Miers, even though they may not be served.

The proposed deal from Fielding came as Senate aides combed through thousands of e-mails and other documents dumped by the Justice Department to show eight former U.S. attorneys weren't fired for political reasons.

Gonzales has been battered by Democrats and some Republicans over his handling of the issue when faced with questions from Congress about the fired federal prosecutors. But Democratic lawmakers said they need to see the role the White House played in the firings.

In his letter Fielding said the 3,000 pages of documents and availability of White House aides should be enough to satisfy the lawmakers while still "respecting the constitutional prerogatives of the presidency."

"In the midst of this current debate, the president must remain faithful to the fundamental interests of the presidency and the requirements of the constitutional separation of powers. We wish to reach a reasonable accommodation so as to provide your committees the information they are seeking in a way that will allow this president, and future presidents, to continue to discharge their constitutional responsibilities effectively," Fielding wrote.

Bush called the type of cooperation he is offering in the investigation "unprecedented."

"In the past 24 hours, the Justice Department has provided more than 3,000 pages ... including those reflecting direct communication with White House staff," Bush said.

Picking Through the Details

Earlier in the day, the Senate voted 94-2 to shut down the ability of the president or attorney general to place a U.S. attorney in a position indefinitely, circumventing the Senate confirmation process.

According to the bill, the White House has 120 days in which to nominate an individual, and if no appointment is made, a federal judge in the district in which a vacancy exists makes the appointment until a nominee can be sent up for review. That's the process that had been in place before Congress updated the Patriot Act a year ago. At that time, the wording was changed so the law allowed the president or attorney general to use emergency powers to appoint U.S. attorneys.

Senate Judiciary Committee ranking member Arlen Specter told "FOX News Sunday" earlier this week that no one noticed the impact the language would have until it was put into application. The fix proposed by Specter and Sen. Dianne Feinstein, D-Calif., returned the language to its previous form.

The document drop seeks to clear up the debate over whether performance or politics caused the firing of the eight attorneys, all Bush appointees.

One e-mail indicates Gonzales got angry when Deputy Attorney General Paul McNulty told Congress last month that an Arkansas prosecutor was fired to make room for Tim Griffin, a former assistant to presidential adviser Karl Rove. Gonzales apparently felt the claim was inaccurate.

"The Attorney General is extremely upset with the stories on the U.S. attorneys this morning," Justice spokesman Brian Roehrkasse, who was traveling with Gonzales in South America at the time, wrote in a Feb. 7 e-mail. "He also thought some of the DAG's statements were inaccurate."

In a statement Monday night, Roehrkasse said he was referring to Gonzales' concerns over the firing of Bud Cummins in Little Rock, who he believed was dismissed because of performance issues. At the hearing, McNulty indicated Cummins was being replaced by a political ally.

But some other e-mails challenge the claim that prosecutors were fired for their performance, and that has oddsmakers betting on whether the attorney general will keep his job.

Among the e-mails that are particularly worrisome are two written by former Gonzales Chief of Staff Kyle Sampson, who in one weighs the prospect of former U.S. Attorney Bud Cummins testifying before Congress.

"I don't think he should," wrote Sampson in the Feb. 1 e-mail. "How would he answer: Did you resign voluntarily? Who told you? What did they say?"

Other questions laid out by Sampson as possible from Congress included: "Did you ever talk to Tim Griffin about his becoming U.S. attorney? What did Griffin say? Did Griffin ever talk about being AG appointed and avoiding Senate confirmation? Were you asked to resign because you were underperforming? If not, then why?"

In another e-mail, Sampson admits he hadn't studied the prosecutor's record. Sampson resigned after other documents suggested he'd misled lawmakers.

In a separate e-mail exchange released, Margaret Chiara, the U.S. attorney in Grand Rapids, Mich., wrote to McNulty on Feb. 1 to inquire "Why have I been asked to resign?"

Early this month, she wrote McNulty again, saying, "I respectfully request that you reconsider the rationale of poor performance as the basis for my dismissal. It is in our mutual interest to retract this erroneous explanation."

She added: "Politics may not be a pleasant reason but the truth is compelling."

Chiara asked McNulty to "endorse or otherwise encourage my selection" as assistant director at the Justice Department's National Advocacy Center, which trains federal, state and local prosecutors.

In one uncomfortable exchange with Chiara, McNulty aide Mike Elston said, "our only choice is to continue to be truthful about this entire matter."

"The word performance obviously has not set well with you and your colleagues," Elston wrote. "By that word we only meant to convey that there were issues about policy, priorities and management/leadership that we felt were important to the Department's effectiveness."

Other e-mails offer rich detail about why some of the U.S. attorneys lost favor in Washington.

John McKay, the prosecutor based in Seattle, circulated an Aug. 30, 2006, letter to McNulty that blasted the Justice Department for delays in creating a database allowing law enforcement to share information on terror cases. The letter was sent to at least some U.S. attorneys.

In an e-mail to McNulty, Chuck Rosenberg, the prosecutor based in Alexandria, Va., said that other U.S. attorneys "are chagrined and embarrassed" over McKay's letter and "are probably happy to let him take the heat."

In the run-up to the firings, McNulty questioned the dismissal of U.S. Attorney Daniel Bogden in Nevada.

"I'm a little skittish about Bogden," McNulty wrote in a Dec. 7 e-mail to Sampson. "He has been with DOJ since 1990 and, at age 50, has never had a job outside government."

Still, McNulty concluded: "I'll admit have not looked at his district's performance. Sorry to be raising this again/now; it was just on my mind last night and this morning."

Meanwhile, The Washington Post reported that unreleased documents indicate Special Counsel Patrick Fitzgerald, who won a conviction against Vice President Cheney's former chief of staff, I. Lewis "Scooter" Libby, earlier this month, was put on a list of prosecutors who had not distinguished themselves.

The list was devised while Fitzgerald was in the middle of the investigation that led to the charges against Libby. Two other prosecutors that ranked in the same range as Fitzgerald were fired.

Click here to read The Washington Post article.

Another Offer of Support to Gonzales

During the news conference, Bush once more expressed his support for Gonzales, as the firings happened on the attorney general's watch.

Bush said it's not unusual to consider whether to accept the resignations of U.S. attorneys at the start of a second term. He added that he decided against a wholesale firing of all 93 attorneys.

"I support the attorney general," Bush said. "These attorneys serve at the pleasure of the president. I appointed them all ... I'm sorry, frankly, that this has bubbled to the surface the way it has, for these attorneys."

On Tuesday morning, Bush called Gonzales directly "to reaffirm his strong backing and support of the attorney general," White House Press Secretary Tony Snow said.

Snow told reporters traveling with the president to Kansas that Bush did not give Gonzales any assurances that he will remain attorney general but "did give him a very strong vote of confidence." Snow added that he didn't know if Gonzales had made an offer to step down.

But neither the new legislation nor Bush's words of support nor the thousands of pages of documents is likely to end Democrats' and some Republicans' calls for Gonzales to resign.

Feinstein and Leahy, D-Vt., complained that many pages of the documents had areas that were whited out before they were sent over.

On top of it all, Colorado Rep. Tom Tancredo called for Gonzales' resignation, saying that the attorney general had failed to enforce the law.

"While I do not believe the dismissal of these eight political appointees warrants Mr. Gonzales' removal, his total mishandling of the affair is simply the latest in a series of leadership failures at the Justice Department," said Tancredo, who has criticized the department over the prosecution of two Border Patrol agents.

If Not Gonzales, Then Who?

With all the talk of a possible resignation from Gonzales, The Politico newspaper has offered up several names of possible replacements.

They include White House homeland security adviser Frances Fragos Townsend, Homeland Security Secretary Michael Chertoff, former Solicitor General Ted Olson, Assistant Attorney General Kenneth Wainstein and federal appeals judge Laurence Silberman and PepsiCo attorney Larry Thompson, who was the government's highest ranking black law enforcement official when he was deputy attorney general during Bush's first term.

"Other names to put on your list, people very familiar to you, former congressman from California, Chris Cox, now the chairman of the Securities and Exchange commission, Larry Thompson, a favorite of the president now with Pepsi. People have even talked about (former Sen.) Fred Thompson of Tennessee and one more name that's out there is the attorney general under President Bush 41, Bill Barr," Mike Allen, who wrote the story for Politico.com, told FOX News.

Click here to read The Politico story.

Asked about the truth of reports of a replacement search, Snow said no such effort is under way.

"The Gonzales reports are just flat false, period," Snow said. "I think what you've got is gossip that people thought was too juicy not to report, unfortunately, for the sake of the people who did the reporting. It's false."

FOX News' Wendell Goler, Catherine Donaldson-Evans and The Associated Press contributed to this report.