A federal appeals court dismissed a House lawsuit Monday seeking to force President Trump’s former White House counsel Donald McGahn to comply with a congressional subpoena, saying that Congress has not passed a law expressly authorizing it to sue to enforce its subpoenas.

The divided 2-to-1 ruling dealt a blow to congressional oversight powers and came three weeks after the full U.S. Court of Appeals for the D.C. Circuit affirmed that Congress had standing to sue — that is, it had shown that the Trump administration’s refusal to allow McGahn to testify harmed the House’s long-standing right to compel testimony from government officials.

The full panel’s ruling returned the case to a three-judge panel of the court to consider other challenges in a historic clash between the branches of government.

In Monday’s opinion, two judges said that despite the injury to Congress, there was no statute by which it could seek a remedy, ending the case.

“This decision does not preclude Congress (or one of its chambers) from ever enforcing a subpoena in federal court; it simply precludes it from doing so without first enacting a statute authorizing such a suit,” Judge Thomas Griffith wrote for the majority, joined by Judge Karen Henderson.

Judge Judith Rogers dissented, saying the Supreme Court has found that Congress’s investigative power includes the authority to compel testimony and enforce a subpoena in federal court.

Congressional power, she wrote, includes “not only a right to information but also a right to seek judicial enforcement of its subpoena.” The Supreme Court has long “held that each House has power to secure needed information” through its constitutional “power of inquiry,” Rogers said. The power is an implicit guarantee of access to the courts for enforcement in addition to the usual ability of parties to seek declaratory court judgments in matters of controversy.

Rogers also rejected McGahn’s contention that he is entitled to “absolute immunity,” a claim the majority did not reach before tossing the case.

“The President does not have absolute, unreviewable discretion to determine what information will be disclosed in response to a subpoena,” Rogers wrote. “Yet that is exactly the nature of McGahn’s absolute immunity claim. By asserting that he need not even appear in response to the Committee’s duly issued subpoena, he in essence contends that the President may unilaterally determine that no information will be disclosed in response to the subpoena.”

The decision marked the second time a circuit court panel voided a House subpoena issued last year to McGahn for his testimony regarding the Trump administration’s alleged obstruction of special counsel Robert S. Mueller III’s investigation of Russian interference in the 2016 U.S. election.

Monday’s ruling also may not be the final word. House Speaker Nancy Pelosi (D-Calif.) announced plans to seek immediate review by the full D.C. Circuit.

“If allowed to stand, this wrong-headed Court of Appeals panel ruling threatens to strike a grave blow to one of the most fundamental Constitutional roles of the Congress: to conduct oversight on behalf of the American people, including by issuing our lawful and legitimate subpoenas,” Pelosi said in a statement. “The ruling represents a flawed judicial attack on the entire House of Representatives; in the past, both Republicans and Democrats have successfully sought to enforce House subpoenas in court.”

Justice Department spokeswoman Kerri Kupec said in an email that “we are pleased” with the court’s ruling.

Monday’s result was foreshadowed in the full circuit’s 7-to-2 decision Aug. 7. Rogers, then writing for the majority, wrote that the “effective functioning of the Legislative Branch critically depends on the legislative prerogative to obtain information, and constitutional structure and historical practice support judicial enforcement of Congressional subpoenas when necessary.”

At that time, it was Griffith and Henderson alone in dissent, emphasizing that courts should not intervene in political disputes.

“Who benefits from today’s decision? Not Congress. The majority’s ruling will supplant negotiation with litigation, making it harder for Congress to secure the information it needs,” Griffith wrote.

Because the majority failed to decide the merits of the case, the chances that McGahn testifies “anytime soon are vanishingly slim,” Griffith added, warning the results would politicize the judiciary “by repeatedly forcing us to take sides between the branches.”

As it turned out, all three were on the three-judge panel to which the full court returned the case.

In a departing opinion, Griffith — who previously announced his retirement from the bench effective Tuesday — got to restate his case.

Legal analysts said that whatever the outcome, the retiring judge was probably correct in predicting that it will take many more months or years for a resolution in the case. Still, they called the decision important, particularly if it is upheld and a future Congress enacts a law authorizing such House suits.

Whether the decision is upheld or reversed, the case would become moot when a new Congress begins next January, unless a new subpoena is issued.

House Democrats subpoenaed McGahn before last year’s formal impeachment investigation of President Trump that ended with Senate acquittal in February. House lawyers argued McGahn’s testimony remained relevant to ongoing oversight and would help the Judiciary Committee determine whether Trump “committed impeachable offenses.”

Trump directed McGahn to disregard the subpoena, saying key presidential advisers are “absolutely immune from compelled congressional testimony.”

The full appeals court issued its decision after the same, split, three-judge panel said courts have no power to resolve a “bitter political showdown.”

The appeals followed a decision from U.S. District Judge Ketanji Brown Jackson, who rejected the White House’s blanket claim of immunity, finding that witnesses instead can invoke executive privilege in person, question by question, after answering subpoenas.