Putting Congress and the White House on a collision course, House and Senate Democrats on Tuesday criticized an offer for top White House aides to give informal interviews to lawmakers about the U.S. attorney firings, while President Bush threatened to go to court if Democrats issue promised subpoenas.

Bush said Tuesday night that it would be “regrettable” if Democrats reject what he called a “reasonable” offer made Tuesday by White House counsel Fred Fielding.

“I will oppose any attempts to subpoena White House officials,” Bush said in a televised statement.

Criticizing Fielding’s proposal, House Judiciary Chairman John Conyers (D-Mich.) today plans to authorize subpoenas for the testimony of presidential adviser Karl Rove and former White House counsel Harriet Miers as well as two of their deputies.

Senate Judiciary Chairman Patrick Leahy (D-Vt.) intends to issue similar subpoenas on Thursday if a counteroffer tendered by Democrats doesn’t produce the desired results.

“Mr. Fielding indicated that he did not want to negotiate, but that doesn’t mean we’re not going to try,” said Sen. Charles Schumer (D-N.Y.), who has been leading the probe on behalf of Senate Democrats.

“We will move forward with the subpoenas on Thursday,” he added.

Meanwhile, the Senate overwhelmingly passed, 94-2, legislation by Sens. Dianne Feinstein (D-Calif.) and Arlen Specter (R-Pa.) designed to limit the president’s power to appoint interim U.S. attorneys.

The White House has indicated it will not oppose the legislation, which would give the Justice Department 120 days to appoint a permanent new U.S. attorney or the power would be handed to a district court judge. But the House has yet to take up the bill.

As the scandal and attendant media circus over the U.S. attorney debacle continued Tuesday, Fielding met with top Congressional Democrats and proposed that Rove and Miers be made available for private interviews, not under oath and without written transcripts.

He also offered to deliver to Congress documented communications between the White House and the Justice Department and between the White House and third parties. He noted in a letter to lawmakers that the White House already has produced 3,000 pages of documents related to the matter, some of which were released Monday night. But Democrats claimed those documents were heavily redacted and only confused matters more.

House and Senate Democrats declared Fielding’s offer insufficient on a variety of fronts.

“We are disappointed,” Conyers said.

Schumer called Fielding’s offer “clever,” but he said the lack of transcripts would do nothing to clear up possibly conflicting testimony and complained that Fielding was not offering intra-White House communications in terms of documents.

Fielding is a “very nice man” and a “very good lawyer,” Schumer said, “but he didn’t offer us what we were looking for. … At best, the offer is incomplete.”

Senate Judiciary Committee member Jeff Sessions (R-Ala.) also attended the meeting and said Fielding’s offer deserved to be considered.

“He made I think a generous proposal that has the potential to be beneficial,” Sessions said.

Asked whether subpoenas inevitably would ensue, Sessions said, “I don’t know.”

In a letter to lawmakers, Fielding offered to make Rove, Miers and two of their deputies available only as a “last resort” after Justice Department officials testified to their involvement in an affair that has some lawmakers calling for the head of Attorney General Alberto Gonzales.

The interviews would be “limited to communications between the White House and persons outside the White House concerning the requests for resignations of the U.S. attorneys in question” and “communications between the White House and Members of Congress concerning those requests.”

The interviews would be conducted jointly between the House and Senate, and questioning would be done by one lawmaker or a “limited number” of Members and would be attended by a member of the White House counsel’s office.

“Such interviews would be private and conducted without the need for an oath, transcript, subsequent testimony or the subsequent issuance of subpoenas,” the letter stated.

But Democrats indicated Tuesday that they were likely to push full steam ahead with their wide-ranging probe of the alleged coordinated campaign between the White House and the Justice Department to oust U.S. attorneys for political reasons.

The Bush administration maintains that eight U.S. attorneys — all Republicans — were ousted last year for perfectly legitimate reasons.

But Democrats allege they were penalized for a lack of political loyalty and that Congress has been misled about the reasons for their firings.

“Our Senate Judiciary Committee will continue to investigate this. I would hope the administration will cooperate with us,” Leahy said at a press conference. “If they don’t, we’ll subpoena them.”

Feinstein indicated that Rove, Miers and their aides should come forward without conditions.

“I don’t think there should be a deal,” she said. “Either they come or they don’t come.”

Rove has never before testified on Capitol Hill, and the Bush administration repeatedly has claimed executive privilege to shield documents and potential aides-turned-witnesses from lawmakers.

After considerable controversy, former National Security Adviser Condoleezza Rice agreed to testify before the Congressionally mandated 9/11 commission, while Tom Ridge also came before Congress when he was assistant to the president for Homeland Security.

But the Bush administration’s record stands in stark contrast to former-President Bill Clinton’s White House, when aides to the president testified a whopping 47 times on a variety of topics, with many prominent aides giving testimony on the Whitewater scandal.