A group of former national security officials expressed their support for the anonymous U.S. official who blew the whistle on President Donald Trump’s dealings with Ukraine, even as Trump and his allies continued to try to discredit the whistleblower.

In an open letter published by the Wall Street Journal, about 90 officials, who served in both Republican and Democratic administrations, said the whistleblower did the right thing, and called on the government and the media to protect his or her identity.

“ “Simply put, he or she has done what our law demands; now he or she deserves our protection.” ”

“We are former national security officials who proudly served in a wide array of roles throughout the U.S. Government,” they wrote. “We are writing about the Intelligence Community whistleblower’s lawful disclosure, which was recently made public. While the identity of the whistleblower is not publicly known, we do know that he or she is an employee of the U.S. Government. As such, he or she has by law the right — and indeed the responsibility — to make known, through appropriate channels, indications of serious wrongdoing. That is precisely what this whistleblower did; and we applaud the whistleblower not only for living up to that responsibility but also for using precisely the channels made available by federal law for raising such concerns.

“A responsible whistleblower makes all Americans safer by ensuring that serious wrongdoing can be investigated and addressed, thus advancing the cause of national security to which we have devoted our careers. What’s more, being a responsible whistleblower means that, by law, one is protected from certain egregious forms of retaliation. Whatever one’s view of the matters discussed in the whistleblower’s complaint, all Americans should be united in demanding that all branches of our government and all outlets of our media protect this whistleblower and his or her identity. Simply put, he or she has done what our law demands; now he or she deserves our protection.”

Officials who signed the letter include former CIA Director John Brennan, former Director of National Intelligence James Clapper and former Secretary of Defense Chuck Hagel. It also included a number of former ambassadors and former officials at the CIA, State Department and Defense Department.

Earlier Sunday, the attorney for the whistleblower said a second individual has come forward with firsthand knowledge of Trump’s Ukraine dealings. While that person has not yet filed an official complaint, they have spoken to the intelligence community’s internal watchdog and can corroborate the original whistleblower’s complaint, the Associated Press reported.

Meanwhile, Trump and his allies continued their attacks against the whistleblowers.

“When it comes to ‘more whistleblowers coming forward’..............I’ve seen this movie before — with Brett #Kavanaugh,” tweeted Sen. Lindsey Graham. “More and more doesn’t mean better or reliable.”

In a series of tweets, Trump on Sunday night called the anonymous whistleblower “highly partisan” and said House Speaker Nancy Pelosi and Democratic Rep. Adam Schiff were guilty of “treason” and should be “impeached.”