Flynn Violated Constitution With Russia Speech, Democrats Say Flynn was seen in a 2015 video appearing with Vladimir Putin at a banquet.

 -- Congressional Democrats are questioning whether President Trump’s new National Security Advisor violated Pentagon policy and the Constitution when he accepted money from a Russian state television network for a speaking engagement.

Democrats made the allegations in a letter to the Pentagon seeking more details about the payments to retired Lt. Gen. Michael Flynn, who has acknowledged the paid engagement to appear with Russian President Vladimir Putin at a televised banquet for the state-owned news channel RT in late 2015 and talk about radical Islam.

Flynn has declined to provide details about any payments from RT, which he has told reporters came through a speaker’s bureau.

“As a retired Army officer, General Flynn was prohibited from accepting direct or indirect payments from foreign governments,” says the Feb. 1 letter signed by Rep. Elijah Cummings, the ranking Democrat on the House Committee on Oversight and Government Reform, along with five other members. “It is extremely concerning that General Flynn chose to accept payment for appearing at a gala hosted by the propaganda arm of the Russian government, which attacked the United States in an effort to undermine our election…”

The letter requests Defense Secretary James Mattis provide Congress all of the pentagon documents on file relating to Flynn’s speaking engagements in Russia, and in any other foreign state.

Because Flynn holds a Top Secret/Sensitive Compartmented Information clearance, he would have been required to report to the Defense Department any repeated contacts or payments from foreign nationals or foreign-owned firms as well as foreign travel.

In an August interview with the Washington Post, Flynn said he saw no problem with attending the event, or with getting paid.

“I was asked by my speaker’s bureau,” he said. “I do public speaking. It was in Russia. It was a paid speaking opportunity. I get paid so much. The speaker’s bureau got paid so much, based on our contract.”

Flynn has been advising Trump on foreign policy matters since at least early 2016, according to published reports.

He was forced to leave his post as director of the Defense Intelligence Agency and retire as three-star general officer in 2014 over his management style and clashes with the Obama administration over policy. Flynn had spent decades as an intelligence officer in the military and oversaw intelligence used to by the U.S. Joint Special Operations Command to kill Iraq's top insurgent leader, Abu Musab al-Zarqawi in 2006, who led the al-Qaeda branch that later became known as ISIS.

After RT broadcast its 10th anniversary gala in December 2015 – which promoted Flynn's appearance as the officer who once led "the country’s main foreign military espionage organization," alongside NSA whistleblower Ray McGovern and Green Party presidential candidate Jill Stein at the head table only feet away from Putin as he made a speech – some senior officials in the intelligence community said it was a shocking judgment call by Flynn.

"He was that close to a despot, an enemy to the U.S., at an event for the Russian government's propaganda arm," a senior U.S. intelligence official said at the time about Flynn's attendance at the RT celebration.

The letter sent by the Democrats today is the latest attempt to invoke an obscure clause in the Constitution, called the “emoluments clause,” which restricts certain U.S. government officials from accepting money from foreign governments.

Congress is responsible for enforcing the emoluments clause and also has the power to exempt someone from it.

White House National Security Council and Defense Department officials did not offer any immediate comment on the Cummings ethics review request when contacted by ABC News.

A spokesman for the chairman of The House Intelligence Committee declined to comment on whether the panel was investigating Flynn as part of its larger probe into Russian interference in the election.

A spokesperson for the Senate Intelligence Committee did not immediately respond to questions about that panel's investigation.

The government watchdog group Citizens for Responsibility and Ethics in Government (CREW) filed a lawsuit against President Trump arguing that his vast global holdings – even while placed under the management of his children – have opened the door to violations of the emoluments clause.

Trump has dismissed the case as frivolous and has argued that removing himself from daily operations of his business has helped to insure he will not face any conflicts of interest while serving in the White House.

Norman Eisen, who served as an ethics advisor to President Obama, serves on the board of CREW and is helping oversee the case against President Trump. He was also consulted in framing questions about Flynn.

“The Members of Congress raise a troubling and important question,” Eisen said in a statement emailed to ABC News. “If Lt. Gen. Flynn is subject to recall, and accepted foreign government funds WITHOUT CONGRESSIONAL CONSENT, then that is a foreign emolument and so a violation of the Constitution. Nor would it be a merely technical one. Concern about the alleged ties between the Trump administration and Russia, and its effect on our national security, is precisely the kind of worry that led the Founders to include this prohibition in the Constitution.”