The House Intelligence Committee is gearing up for a potential court battle over a controversial whistleblower complaint that a top Democrat believes is likely linked to President Donald Trump.

After a four-hour, closed-door briefing with inspector general of the Intelligence Community Michael Atkinson, committee chairman Adam Schiff said the Department of Justice is involved in preventing lawmakers from learning about the contents of the complaint, claiming that it involves privileged information.

Schiff said that the committee is currently weighing its options about how best to move forward. He added they are consulting with House general counsel Douglas Letter, and that they may go to court to request a temporary restraining order or some other form of "urgent relief" in order to obtain the information.

However, Schiff signaled that such a decision would come after acting director of national intelligence Patrick Maguire testifies before the panel next week about the whistleblower matter.

"I would imagine that if it comes down, that we have to go to court to get this, that we would have a very good case to seek a temporary restraining order or a mandamus or some urgent form of relief, because the IG has said we cannot wait," Schiff said.

"So it's not a situation where we can afford to go through weeks or months of litigation within this court or that court. There's an urgency here that I think the courts will recognize," he continued. "I hope that that's not necessary and I hope that the DNI will reconsider because it's my understanding that by law he can provide this to us, and that by law he is required to provide this to us."

Such an effort in the courts would mark yet another legal battle between House Democrats and the Trump administration. There are already several lawsuits surrounding lawmakers' efforts to obtain the president's private financial records.

But this lawsuit would be markedly different than the others, as it would not seek information that lawmakers say they need to investigate the president as they weigh possible impeachment. Rather, Schiff argues that Congress should have been given this information as part of its oversight duties, and that it is being unduly withheld.

Members of the committee exiting the briefing said the inspector general did not share details about the whistleblower complaint itself. Schiff said the official was not authorized to reveal that information.

The controversy over the whistleblower complaint began last week when Schiff subpoenaed Maguire for the details of the allegation, claiming that the information was being "improperly withheld."

The Democratic chairman pointed to the inspector general's finding that the complaint was "urgent," and that a federal statute would require the ODNI to share that information with Congress.

"As acting director of national intelligence, you have neither the legal authority nor the discretion to overrule a determination by the IC IG. Moreover, you do not possess the authority to withhold from the Committee a whistleblower disclosure from within the Intelligence Community that is intended for Congress," Schiff wrote at the time

General counsel for ODNI Jason Klitenic responded in a letter earlier this week, writing that the office believed the complaint does not meet the standards laid out in the statute needed for it to be disclosed with Congress.

But Schiff said Thursday that a question of whether the information is privileged and therefore can't be given to lawmakers is now being raised by the Justice Department. And he questioned why Maguire sought an opinion from DOJ.

"Who is in a position to influence an acting director of national intelligence who has not been on the job very long, to do something completely unprecedented, which is to go outside of his own agency and seek an opinion about whether he has to provide this to Congress?" Schiff asked.

The chairman said the claims of privilege over the information indicates that the complaint involves either the president or his top advisers.

According to a letter released Thursday by Schiff's committee, Atkinson wrote to lawmakers earlier this week that despite his hopes that the Maguire might allow him to tell the whistleblower about how to contact the congressional committees directly, he and the DNI "are at an impasse over this issue."

"I understand that I am bound by the determination reached as a result of the Acting DNI's consultations with DOJ, and the ICIG will continue to abide by that determination," said Atkins, a former partner at Winston & Strawn.

"I, nevertheless, respectfully disagree with that determination, particularly DOJ's conclusion, and the Acting DNI's apparent agreement with the conclusion."

And he said the "unresolved difference" are currently "affecting the execution of two of my most important duties and responsibilities as the Inspector General of the Intelligence Community"—his obligations toward the person behind the complaint, and his responsibility to inform lawmakers on intelligence committees about the issues.

Robert Litt, the former general counsel for ODNI and current of counsel at Morrison & Foerster, said that there were instances in his previous job where he reached out to the Department of Justice's Office of Legal Counsel for advice. Litt added that he believes Maguire made the right decision by consulting the White House, if the complaint did implicate the president.

However, he said the letters written by Klitenic, the current ODNI general counsel, didn't read like ones typically sent by the intelligence office and were similar to ones issued by OLC.

"I'm quite certain this decision was driven by the Department of Justice, and perhaps the White House counsel's office," Litt said.

Still, Litt said it would be difficult to say exactly how Klitenic should have acted in this situation without knowing exactly what the underlying complaint alleged.

The Washington Post reported late Wednesday that former national security officials say the complaint surrounds a contact Trump had with a foreign leader and a promise the president made to that leader.

Schiff said Thursday that he did not know if the reports about the complaint are accurate, as he did not know the contents of the complaint.

Trump also denied The Post's reporting in a tweet sent during Thursday's briefing, saying that whenever he talks with a foreign leader, he knows that U.S. intelligence officials may also be on the call.

"Knowing all of this, is anybody dumb enough to believe that I would say something inappropriate with a foreign leader while on such a potentially 'heavily populated' call," Trump wrote.

Lawmakers are zeroing in on the word "shall" in the statute in saying that the complaint should have been disclosed to Congress.

"The word is 'shall,' shall be sent to the committees of jurisdiction," Intelligence Committee member Rep. Jackie Speier told reporters as she exited the briefing. "And in this case that hasn't happened. It's been deemed to be urgent. Urgent means urgent."

She added that she found the subject matter of the complaint to be "deeply troubling."

Schiff said Thursday that he is concerned about the impact this battle could have on whistleblower statutes.

"I don't think this is a problem of the law, I think the law is written very clearly, I think the law is just fine. The problem lies elsewhere," Schiff said. "And we're determined to do everything we can to determine what this urgent concern is to make sure that national security is protected and to make sure this whistleblower is protected."

David Colapinto, general counsel for The National Whistleblower Center, said that going to court could be a risky move for the House, as it's unclear exactly how long the litigation could take—or if a judge would even rule in their favor.

He said that issues like who can have access to allegedly privileged information could raise tricky legal questions that ultimately could make their way to the U.S. Supreme Court.

"You don't get to the Supreme Court in a week or a month," Colapinto said. "This statute says, this is the process to communicate an urgent whistleblower concern. We're already over a month in. So how long does it take for a whistleblower to communicate an urgent concern to Congress?"

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