Washington(CNN) President Donald Trump on Friday lost his appeal to stop a House subpoena of his tax documents from his longtime accountant Mazars USA.
In a 2-1 ruling, the US Court of Appeals for the District of Columbia Circuit upheld a lower court ruling saying the firm must turn over eight years of accounting records.
The opinion is a strong signal that the White House's letter earlier this week refusing to cooperate with the impeachment probe without a full House vote authorizing it would not hold up in court.
The court specifically weighed in on this idea, writing it has "no authority" to require the House to take a full vote in support of a subpoena to investigate the President, citing the Constitution.
"The courts lack the power to invalidate a duly authorized congressional subpoena merely because it might have been 'better [if]...the full House' had specifically authorized or issued it," the court wrote. "Unless and until Congress adopts a rule that offends the Constitution, the courts get no vote in how each chamber chooses to run its internal affairs."
It's the first major case at the appeals court level in the ongoing standoff between the House and Trump. The President has lost all of his challenges so far that have been decided at the trial court level to stop House subpoenas.
Trump may appeal to the Supreme Court to stop Mazars, but courts, including the Supreme Court, previously have refused to curtail Congress' subpoena power.
"We are reviewing the opinion and evaluating all appellate options," said Trump attorney Jay Sekulow.
In a statement, the accounting firm wrote: Mazars USA will respect the legal process and fully comply with its legal obligations. We believe strongly in the ethical and professional rules and regulations that govern our industry, our work and our client interactions. As a matter of firm policy and professional rules we do not comment on the work we conduct for our clients."
Trump will have seven days to ask for another appeal on the decision endorsing the House's subpoena of his tax documents.
Judges David Tatel, an appointee of President Bill Clinton, wrote the majority opinion, joined by Judge Patricia Millett, an appointee of President Barack Obama. Trump appointee Judge Neomi Rao dissented.
The appeals court broadly supported the House's power to subpoena information about Trump as it investigates him and considers laws in response, calling the subpoena "valid and enforceable."
"A congressional committee, as committees have done repeatedly over the past two centuries, issued an investigative subpoena, and the target of that subpoena, questioning the committee's legislative purpose, has asked a court to invalidate it," the majority opinion states. "The fact that the subpoena in this case seeks information that concerns the President of the United States adds a twist, but not a surprising one."
Though the court's decision was split, the case is widely considered to be a tough one for Trump, even with support from the Justice Department.
"We detect no inherent constitutional flaw in laws requiring presidents to publicly disclose certain financial information. And that is enough," the opinion states.
The documents the House seeks are relevant to the investigation, the majority said.
"Just as a congressional committee could not subpoena the President's high school transcripts in service of an investigation into K-12 education, nor subpoena his medical records as part of an investigation into public health, it may not subpoena his financial information except to facilitate an investigation into presidential finances" the majority opinion states.
In her dissent, Rao adopts the argument from Trump and House Republicans that the efforts to get Trump's personal documents cannot be done simply under Congress's investigative power.
"The Constitution and our historical practice draw a consistent line between the legislative and judicial powers of Congress. The majority crosses this boundary for the first time by upholding this subpoena investigating the illegal conduct of the President under the legislative power," Rao wrote.
"Investigations of impeachable offenses simply are not, and never have been, within Congress's legislative power," Rao said. "Throughout our history, Congress, the President, and the courts have insisted upon maintaining the separation between the legislative and impeachment powers of the House and recognized the gravity and accountability that follow impeachment."
Rao added: "Allowing the Committee to issue this subpoena for legislative purposes would turn Congress into a roving inquisition over a co-equal branch of government."
This story has been updated.