Democrats portrayed the subpoena authority, approved on voice vote by both the House and Senate Judiciary committees, as a bargaining chip in negotiations over the terms of any testimony by White House political adviser Karl Rove.
The committees' chairmen, Sen. Patrick Leahy, D-Vt., and Rep. John Conyers, D-Mich., appeared in no rush to issue subpoenas to White House officials. and provoke a standoff.
Talks continued behind the scenes, officials said, even as the White House and majority Democrats engaged in strategic posturing before the cameras.
In letters Thursday, Senate and House Democrats rejected White House counsel Fred Fielding's offer to let Rove and other administration officials talk about their roles in the firings, but only on Bush's terms: in private, off the record and not under oath.
"I have never heard the Senate take an ultimatum like that," Leahy said. "I know he's the decider for the White House. "But he's not the decider for the United States Senate."
"Your proposal will not facilitate a full and fair inquiry," wrote Conyers and Rep. Linda Sanchez, D-Calif.
Nonetheless, the offer stands, White House spokeswoman Dana Perino said. ""Unfortunately, these letters show they aren't as interested in ascertaining the facts than going on a political fishing expedition," she said.
Presidential press secretary Tony Snow cast the administration's offer to allow Rove, former White House counsel Harriet Miers and their deputies talk to lawmakers in private as the best deal Democrats are going to get.
"We opened with a compromise," Snow told reporters. "By our reaching out, we're doing something that we're not compelled to do by the Constitution." But, he added, "The phone lines are still open."
Sen. Arlen Specter, the Senate committee's former chairman, insisted room for compromise remains. "Rejections in a news conference don't count," said Specter, R-Pa. "Rejections eyeball to eyeball count."
He suggested the committees could grant the president's demand that his aides not be required to take an oath, but persuade the White House to allow public proceedings with perhaps 16 House and Senate Judiciary Committee members asking questions. Specter told reporters Thursday afternoon that he spoke with Fielding about his idea.
Fielding said he would convey Specter's proposal to the president. "Mr. Fielding did not accept or reject it," Perino said.
Specter also said the situation might benefit from time. "The dust has to settle first," he said.
On that, Snow agreed: "We're going to let this thing simmer a little bit and let people reflect on it."
The developments came as Attorney General Alberto Gonzales, struggling to save his job from increasing calls for his resignation over the firings, promised to cooperate with Congress.
"I'm not going to resign," Gonzales told reporters after an event in St. Louis, the first of a series of meetings with federal prosecutors in coming days in an apparent attempt to patch up relations tattered by the scandal.
"No United States attorney was fired for improper reasons," Gonzales said.
Rep. Paul Gillmor, R-Ohio, said Gonzales has become a "lightning rod" for criticism, joining a growing number of GOP lawmakers who want Gonzales out. "It would be better for the president and the department if the attorney general were to step down," Gillmor said.
Members of both parties want to know why the Justice Department fired eight well-regarded U.S. attorneys over the winter; whether politicians pressured the prosecutors to rush corruption cases; and whether the firings were punishments for the prosecutors' balking at Bush administration priorities.
Lawmakers also want answers on whether the firings were to make way for more loyal Bush allies, as was done in Arkansas.
Gonzales has said that he intends to submit every replacement appointee to the confirmation process. But an e-mail from his then-top aide suggests the intent was to use delays that would let the replacement prosecutors serve without Senate approval through the rest of Bush's term.
Such inconsistencies have engulfed Gonzales in an uproar in which the administration is accused of crossing a fine line that allows presidents to replace federal prosecutors, but not if the intent is to influence investigations. It is customary for presidents to replace all 93 U.S. attorneys at the beginning of a term in office, but not to single out a few in midterm. The Senate committee voted to approve, but not issue subpoenas for Rove, former White House counsel Harriet Miers and her former deputy, William Kelley. A House subcommittee's motion on Wednesday on subpoenas also included J. Scott Jennings, who works for Rove. Leahy and Specter also have asked Gonzales' former top aide Kyle Sampson - who has resigned - to testify voluntarily next week. The panel approved a subpoena for Sampson last week. Bradford Berenson, Sampson's lawyer, requested a delay until April 2 at the earliest, to give his client "more time to review the matter" and to allow Berenson to take a previously scheduled vacation.