If subpoenas are issued demanding White House aides testify on the firing of eight former U.S. attorneys, then President Bush will have no choice but to withdraw his offer to have his staff meet with congressional lawmakers informally, Press Secretary Tony Snow said Wednesday.

Presumptively, that would also include the offer to give over any remaining unreleased documents from the White House over the dismissal of the federal prosecutors.

Snow spoke after a House panel authorized subpoenas for at least five White House aides, including political director Karl Rove and former counsel Harriet Miers. The move is the latest in a brewing battle between congressional Democrats and Bush over the extent to which the assistants should respond to inquiries.

Snow said subpoenas will make evident that the president's offer to have the aides answer questions about their roles in the decision to fire the federal prosecutors has been rejected.

"There is an important distinction between authorizing subpoenas and issuing them. And we hope members of Congress, as they have an opportunity to think this through, are going to realize that they've got a deal before them that enables them to find out what the truth is," Snow told reporters.

"We are doing this in a way that not only preserves presidential prerogatives but also creates an atmosphere that's going to be conducive to working together and to proceed in a manner that's dignified, thorough and accurate," he said.

Snow also suggested that the Democrats are looking for a fight rather than the truth.

"This is not a hearing. It's not a trial. It's an interview. ... We have offered them everything that gives them access to the facts and truth. If they do not accept the offer, it lifts the veil on some of the motivations, which means that people are less interested in the truth than creating a political spectacle," Snow said.

"It appears that there is more an effort to try to single out individuals rather than to try to isolate the truth," he continued.

The House Judiciary Subcommittee on Commercial and Administrative Law on a voice vote approved the panel chairman's authority to compel the president's top aides to testify publicly and under oath about their roles in the firings.

House Judiciary Committee Chairman Rep. John Conyers, D-Mich., is now able to issue the subpoenas should he choose. He may also force the White House, the subpoenaed presidential aides and Department of Justice to turn over documents.

"We have worked toward voluntary cooperation on this investigation, but we must prepare for the possibility that the Justice Department and the White House will continue to hide the truth," subcommittee chairwoman Linda Sanchez, D-Calif., said before the vote.

"This Congress respects executive privilege as a safeguard for the internal deliberations on the legitimate creation of policy. However, the White House has begun claiming executive privilege as a blanket excuse against any oversight into potential abuse of power or political misconduct," she added.

The Senate Judiciary Committee is scheduled to follow suit on Thursday. Committee Chairman Patrick Leahy would then consult with ranking member Sen. Arlen Specter about issuing subpoenas, but the ultimate power to issue them would reside with the chairman.

Specter called an emergency meeting of committee Republicans to discuss the subpoena issue. Sentiment appeared to be growing among them not to oppose the subpoenas. Sen. Charles Grassley, R-Iowa, told FOX News, "If you want information out now, that's the only way you get it."

Specter and Leahy sent a letter late Wednesday to Kyle Sampson formally requesting his appearance at a hearing next Thursday before the committee. Leahy told FOX News that the letter made clear that a subpoena will be issued if Sampson refuses to appear. The committee authorized a subpoena for Attorney General Alberto Gonzales' former chief of staff last week. Leahy only needs to sign it for it to be official.

In calling for the subpoenas, Democrats appear to be rejecting the offer made by Bush late Tuesday to allow Miers and Rove — as well as deputy White House counselors William Kelley and J. Scott Jennings and Rove deputy Sara Taylor — to speak to judiciary panel members and staff. The president insisted that the consultations be given privately and not under oath.

Bush said his aides are free to speak with lawmakers and their staff to explain how the decisions to oust the prosecutors were made. He also agreed to release "all White House documents and e-mails involving direct communications with the Justice Department or any other outside person, including members of Congress and their staff, related to this issue."

The president said any efforts by Democrats to go on a "partisan fishing expedition aimed at honorable public servants" will be met with resistance. He said he would "absolutely" take the matter to court if it went that route.

"It will be regrettable if they choose to head down the partisan road of issuing subpoenas and demanding show trials when I have agreed to make key White House officials and documents available. I have proposed a reasonable way to avoid an impasse. I hope they don't choose confrontation. I will oppose any attempts to subpoena White House officials," Bush said.

Shortly before the panel authorized subpoena power for its chairman, Snow warned, "You don't need a showdown here."

Snow said the offer to make the advisers available for interviews is generous and reasonable. He asked, "What's more important, the truth or a spectacle?"

Before the vote on the subpoenas, Conyers turned up his nose at the offer.

"Well, we could meet at the local pub to have that kind of a gathering. I love conversations, especially with veteran lawyers and people associated with the White House. It'd be a great conversation, but in my judgment, it would not advance us toward uncovering the simple truth in this matter," he said.

He also urged Republican panel members to join Democrats in the authorization and said the subpoenas would be held in abeyance if the White House continued to cooperate with members of Congress.

Republicans weren't biting. Florida Rep. Ric Keller, the ranking Republican on the subcommittee, said the panel has a right to subpoena Rove and Miers, and Bush has a right to invoke executive privilege to protect them. Snow also said the White House will only provide documents about the fired U.S. attorneys if Democrats accept the restrictions.

The Fight Over Appearances

Democrats put out talking points after the president's remarks listing some of the 74 times "in recent history" that they say presidential advisers have testified to Congress, including 47 instances during the Clinton administration when Congress was led by Republicans.

Without a public hearing, record of testimony in the form of a transcript or a statement made under oath, argued Sen. Chuck Schumer, D-N.Y., nothing will be accomplished.

"We Democrats want to resolve this issue quickly. We want to get the facts, we want to find out what went wrong, and it's clear many things did. We want to correct them and move on. But when the president gives an offer that really doesn't allow the truth to be gotten — no oaths, no transcripts, no public testimony — it doesn't serve the purpose of finding out what happened, resolving (it) quick in a fair and unpartisan way and moving on," Schumer said on the Senate floor Wednesday.

Gonzales has been battered by Democrats and some Republicans over the various explanations given as to why the federal prosecutors were fired. At one point, Justice Department officials said the firings were performance-based. The attorneys, who serve at the pleasure of the president, claimed the removals were political.

"Now that the record is out there in black and white for the rest of the country to see, the argument that we were fired for 'performance related' reasons (in the words of Deputy Attorney General Paul McNulty) is starting to look more than a little wobbly," fired Attorney David Iglesias wrote in Wednesday's New York Times.

Click here to read Iglesias' op-ed.

Calls for Gonzales' resignation have been abundant among Democrats, and even some Republicans have said they would like him to go. On Wednesday, however, GOP Conference Chairman Adam Putnam stopped short of asking for Gonzales' resignation, but said Gonzales "is standing in the center of a tornado of his own making." He said much of the attorney general's future rides on his testimony when he finally does end up on Capitol Hill.

Speaking to reporters, Bush also thanked the dismissed attorneys for their service but said nothing is unusual about his decision to replace any of them.

"The start of a second term is a natural time to discuss the status of political appointees within the White House and with relevant agencies, including the Justice Department. In this case, the idea was rejected and was not pursued," Bush said.

While the administration has rejected the service of the eight prosecutors, the White House announced Wednesday that the president plans to nominate another U.S. attorney, Michael J. Sullivan of Massachusetts, to be director of the Bureau of Alcohol, Tobacco, Firearms and Explosives at the Department of Justice. Sullivan has been acting director since September 2006.

FOX News' Wendell Goler and Trish Turner and The Associated Press contributed to this report.