The chairmen of two congressional committees issued subpoenas Monday for testimony from former White House counsel Harriet Miers and former political director Sara Taylor on their roles in the firings of eight federal prosecutors.

Democrats probing whether the White House improperly dictated which prosecutors the Justice Department should fire also are subpoenaing the White House for all relevant documents.

Senate Judiciary Committee Chairman Patrick Leahy of Vermont issued Taylor's subpoena for her testimony July 11. His counterpart in the House, Judiciary Committee Chairman John Conyers of Michigan, issued a subpoena for Miers' testimony the next day.

The White House has repeatedly refused to make current and former officials involved in the firings available except in private interviews, without transcripts. Congressional investigators have refused that offer.

"The committees can easily obtain the facts they want without a confrontation by simply accepting our offer for documents and interviews,"White House spokeswoman Dana Perino said Wednesday. "But it's clear that Sen. Leahy and Rep. Conyers are more interested in drama than facts."

Miers left the White House Jan. 4, while Taylor's last day was May 30.

The House and Senate chairmen implicitly threatened a constitutional showdown if the White House does not comply — or strike a deal.

"The breadcrumbs in this investigation have always led to 1600 Pennsylvania," said Conyers, D-Mich. "This investigation will not end until the White House complies with the demands of this subpoena in a timely and reasonable manner so that we may get to the bottom of this."

"The White House cannot have it both ways — it cannot stonewall congressional investigations by refusing to provide documents and witnesses, while claiming nothing improper occurred," Leahy added.

Technically, if the showdown between the White House and Congress is not resolved, the matter could end up with House and Senate contempt citations and a session in federal court.

Congressional officials knowledgeable about the probe painted a dark picture of what the Democratic-led committees might do if the White House refuses to comply.

One option, these officials said, are votes in committee and on the House and Senate floors on contempt citations against any subjects of the subpoenas who don't comply. Another, according to one aide, is a subpoena for White House Counsel Fred Fielding, compelling him to testify publicly about the Bush administration's reasons if the subpoenas are ignored. The officials spoke on condition of anonymity because the White House, Miers and Taylor had not yet responded to the subpoenas.

Sen. Arlen Specter, R-Pa., pointed out that a resolution without a constitutional showdown is in both sides' interests.

"I don't believe in threats," he said in a telephone interview, adding that he hopes to negotiate with Fielding later in the day. "I believe in taking it a step at a time."

Miers and Taylor did not immediately respond to requests for comment.

Democrats have widely demanded that Gonzales step down over the firings and his general stewardship of the Justice Department. Seven Senate Republicans voted with Democrats Monday on a no-confidence resolution against Gonzales and many more members of the GOP have called publicly for a new attorney general. The resolution fell seven votes short of the 60 required to advance it to a formal up-or down vote.

For his part, Gonzales has said he plans to stay until the end of Bush's second term, and the president continues to stand by his longtime friend.

The subpoenas come a day after newly-released Justice Department documents revealed that Taylor was closely involved in the firings. In a Feb. 16 e-mail, Taylor described a U.S. attorney in Arkansas who was fired last year as "lazy" — "which is why we got rid of him in the first place," according to the documents.

Former prosecutor Bud Cummins, reached Tuesday night for comment, responded: "I'm sure I have some faults, but my work ethic hasn't been one them." Taylor also complained that Deputy Attorney General Paul McNulty told senators that Cummins was replaced at the urging of Miers, then White House counsel.

It's the first time during the five-month investigation that Congress is compelling testimony from White House insiders over the firings. Not yet on the subpoena list is President Bush's top political adviser, Karl Rove, but only because Democrats have not yet finished interviewing those below him, the officials said.

Democrats say the firings are evidence that Attorney General Alberto Gonzales allowed his traditionally independent federal law enforcement agency to be run, in effect, by the White House.

Republicans point out that U.S. attorneys serve at the president's pleasure and can be fired for any reason, or none at all. Former and current top Justice Department officials have said the list of the eight fired was drawn up on the advice of several senior officials. E-mails made public have shown that Miers, Taylor and Rove were looped into the decisionmaking process and attended meetings on the firings.