The judiciary committee of the US House of Representatives has voted to file a contempt of Congress charge against two White House aides.
The two aides ignored a Congressional subpoena to testify
The move is seen as an escalation of a row over the firing of eight federal prosecutors, correspondents say.
President George W Bush invoked executive privilege earlier in July to stop the two aides from testifying to Congress over the sackings.
The contempt charge must be approved by the full House of Representatives.
The charge carries a possible jail sentence of a year.
Congress has held a series of hearings into whether the firing of the prosecutors was politically motivated, as opponents of President Bush say.
The two aides - White House chief of staff Joshua Bolten and and former legal counsel Harriet Miers - failed to comply with subpoenas to testify to Congress over the dismissals.
The White House claims that President Bush has the right to reject Congressional requests for documents or testimony from staff members.
Harriet Miers is President Bush's former top lawyer
"I am hopeful that today's vote will help the administration see the light and release the information to which the Judiciary Committee is entitled," said House Speaker Nancy Pelosi, a Democrat.
She said the contempt proceedings were "part of a broader attempt by House Democrats to restore our nation's fundamental system of checks and balances".
"In our view this is pathetic," said White House spokesman Tony Snow.
"What you have right now is partisanship on Capitol Hill that quite often boils down to insults, insinuations, inquisitions and investigations."
On Tuesday, Attorney General Alberto Gonzales faced tough questioning from the Senate Judiciary Committee over the dismissed prosecutors as well as the White House's use of wire-tapping for terrorism surveillance.
Federal prosecutors work under the direction of the attorney general but can be dismissed at any time at the discretion of the president.
Mr Bush has resisted repeated calls to sack Mr Gonzales, who denies any wrongdoing in connection with the sacked prosecutors.