WASHINGTON — The Bush administration is raising the stakes in a court fight that could change the balance of power between the White House and Congress.

Lawyers for the Justice Department said yesterday that they will soon ask a federal appeals court not to force the president’s top advisers to comply with congressional subpoenas next month. President Bush argues Congress doesn’t have the authority to demand information from his aides.

A U.S. District Judge, John Bates, strongly rejected that stance last month, ordering the former White House counsel, Harriet Miers, to testify and the White House chief of staff, Joshua Bolten, to turn over documents related to the firing of federal prosecutors.

It was a historic loss for the Bush administration, a stinging ruling in the first such case ever to make it to the courts.

The House Judiciary Committee responded swiftly, demanding Ms. Miers appear September 11 as it investigates whether federal prosecutors were inappropriately fired as part of a White House effort to politicize the Justice Department.

The Bush administration had already indicated it would appeal but Justice Department lawyers said yesterday that they will ask the court to step in quickly and temporarily put Ms. Miers’ appearance on hold while the appeal plays out. It’s a risky move for an administration that has spent years trying to strengthen the power of the presidency.

If the appeals court refuses to temporarily block the testimony, it would essentially be endorsing Mr. Bates’s ruling against the Bush administration. Ms. Miers likely would have to comply with the subpoena, setting a precedent that would give Congress new teeth in its investigations and weaken future presidents.

On the other hand, if the appeals court temporarily blocks Ms. Miers’ testimony, it could allow the Bush administration to run out the clock before a new Congress comes to Washington and the case becomes moot. In that situation, Mr. Bates’s order will have been weakened and future presidents will have more wiggle room.

The Bush administration could have taken other steps to avoid a showdown at the appeals court. Even if it appealed Mr. Bates’ ruling, it could have negotiated a deal with Congress in which Ms. Miers and Mr. Bolten provided some information voluntarily and lawmakers agreed to withdraw the lawsuit.

But House counsel Irv Nathan said negotiations have been “completely useless.”

“We have not found willing partners on the other side of the table,” Nathan said in court Wednesday, Mr. telling Bates that “we’re being dunced around here.”

A Justice Department attorney, Carl Nichols, called those statements misleading but declined to elaborate. He said the Justice Department would file documents with the appeals court by today asking the judges to step in.