As promised, House Speaker Nancy Pelosi announced that she has given the Judiciary Committee authority to file a lawsuit against Bolten and Miers in federal court.
"The House shall do so promptly," she said in a statement.
Mukasey said Bolten and Miers were right in ignoring subpoenas to provide Congress with White House documents or testify about the firings of federal prosecutors.
"The department will not bring the congressional contempt citations before a grand jury or take any other action to prosecute Mr. Bolten or Ms. Miers," Mukasey wrote Pelosi.
Pelosi shot back that the aides can expect a lawsuit.
"The American people demand that we uphold the law," Pelosi said. "As public officials, we take an oath to uphold the Constitution and protect our system of checks and balances and our civil lawsuit seeks to do just that."
The suit had a political purpose too. Democrats have urged that the filing occur swiftly so that a judge might rule before the November elections, when all 435 House seats and a third of the Senate are up for grabs. Criticism of Bush's use of executive power is a key tenet of the Democrats' platform, from the presidential race on down.
The House voted two weeks ago to cite Bolten and Miers for contempt of Congress and seek a grand jury investigation. Most Republicans boycotted the vote.
Pelosi requested the grand jury investigation on Thursday and gave Mukasey a week to reply. She said the House would file a civil suit seeking enforcement of the contempt citations if federal prosecutors declined to seek misdemeanor charges against Bolten and Miers. The plaintiffs would be the entire Judiciary Committee, who would be represented by the House's lawyers, according to aides to Pelosi and committee Chairman John Conyers, D-Mich.
Mukasey took only a day to get back to her. But he had earlier joined his predecessor, Alberto Gonzales, in telling lawmakers they would refuse to refer any contempt citations to prosecutors because Bolten and Miers were acting at Bush's instruction.
A civil suit would drag out a slow-motion crawl to a constitutional struggle between a Democratic-run Congress and a Republican White House that has been simmering for more than a year.
Democrats say Bush's instructions to Miers and Bolten to ignore the House Judiciary Committee's subpoenas was an abuse of power and an effort to block an effort to find out whether the White House directed the firing of nine U.S. attorneys in 2006 for political reasons.
Republicans call the whole affair a political game and walked out of the House vote on the contempt citations in protest.
The 223-32 House vote on a resolution approving the contempt citations Feb. 14 was the first of its type in 25 years. The White House pointed out that it was the first time that such action had been taken against top White House officials who had been instructed by the president to remain silent to preserve executive privilege.
In his letter, received by the House early Friday evening, Mukasey pointed out that not only was Miers directed not to testify, she also was immune from congressional subpoenas and was right to not show up to the hearing to which she had been summoned.
"The contempt of Congress statute was not intended to apply and could not constitutionally be applied to an executive branch official who asserts the president's claim of executive privilege," Mukasey wrote, quoting Justice policy.
"Accordingly," Mukasey concluded, "the department has determined that the noncompliance by Mr. Bolten and Ms. Miers with the Judiciary Committee subpoenas did not constitute a crime."
Though they were not surprised, Democrats reacted to Mukasey's letter with outrage.
"Today's decision to shelve the contempt process, in violation of a federal statute, shows that the White House will go to any lengths to keep its role in the U.S. attorney firings hidden," said Conyers. "In the face of such extraordinary actions, we have no choice but to proceed with a lawsuit to enforce the committee's subpoenas."