WASHINGTON — The government’s inspectors general sharply criticized a Justice Department ruling from last month that determined that the whistle-blower complaint about President Trump’s call with Ukraine’s leader should not go to Congress.
The opinion could “seriously impair whistle-blowing” and deter intelligence officials from reporting waste, fraud and misconduct, about 70 inspectors general from across the government warned in the letter, dated Oct. 22 and released on Friday.
“Whistle-blowers play an essential public service in coming forward with such information, and they should never suffer reprisal or even the threat of reprisal for doing so,” wrote the inspectors general, who serve as independent watchdogs for their agencies.
The inspectors general, who are tasked with detecting and deterring fraud in the federal government, are a mostly nonpartisan group, and it is unusual for them to wade into a political fight or come together to criticize a ruling from the Justice Department.
The Sept. 3 ruling by Steven A. Engel, the assistant attorney general who leads the department’s Office of Legal Counsel, effectively sounded alarms among House Democrats that the Trump administration was trying to block a complaint from a whistle-blower. Within days, revelations that the complaint involved Mr. Trump and Ukraine helped prompt their impeachment inquiry.
The whistle-blower is a C.I.A. officer who has not identified himself publicly. President Trump has frequently criticized the whistle-blower and likened him to a spy. Nearly a month ago, he complained in a tweet that his administration could not “interview & learn everything about” the whistle-blower.
The letter, from the Council of the Inspectors General on Integrity and Efficiency, called on Mr. Engel to withdraw or modify his opinion.
In a response letter, Mr. Engel pushed back, reiterating the arguments in his original memo that the whistle-blower’s complaint did not involve a member of the intelligence community under the jurisdiction of the director of national intelligence. The Justice Department, he wrote, was interpreting the relevant statutes as Congress had written them.
“We are confident that our opinion does not diminish the statutory protections that Congress has provided to federal employees and contractors who make good-faith disclosures to inspectors general,” Mr. Engel wrote.
In his ruling, Mr. Engel effectively led the acting director of national intelligence, Joseph Maguire, to block the whistle-blower’s complaint from going to Congress. The inspector general for the intelligence community, Michael Atkinson, had wanted to forward it to lawmakers.
The ruling touched off a standoff among Mr. Atkinson, Mr. Maguire and Representative Adam B. Schiff, Democrat of California and the head of the House Intelligence Community.
Under pressure from Mr. Schiff, Mr. Maguire brokered a compromise that allowed the complaint go to lawmakers, who released an unclassified version of it.
The Justice Department memo, which remains in effect, found that to qualify as an urgent concern, any whistle-blower complaint made to the intelligence agencies’ inspector general had to be about the funding, administration or operation of an intelligence agency. The memo found that the interference alleged by the whistle-blower did not meet that standard.
The Justice Department memo could allow executive branch officials going forward to overrule an inspector general’s determination that a matter was an urgent concern that warrants notifying members of Congress.
Lawyers for the whistle-blower and support organizations for whistle-blowers had roundly criticized the Justice Department ruling, saying it threated to effectively gut protections for government officials trying to report wrongdoing as well as Congress’ ability to conduct oversight of the executive branch.
“In one memo, the Department of Justice has sought to undermine federal law and reverse decades of work of what effectively encompasses the mechanisms for robust oversight of the federal government,” said Andrew P. Bakaj, the lead lawyer for the whistle-blower.
The system of inspectors general was built up in the 1970s, after Watergate and allegations that the Justice Department had become politicized. The statutes creating various inspectors general positions all provided for them to send concerns to Congress.
But the Justice Department opinion, whistle-blower groups said, gives the White House an effective veto on congressional oversight.
Until Mr. Engel wrote the memo, many experts did not think the Justice Department could second-guess the intelligence community’s inspector general, said John Kostyack, the executive director of the National Whistleblower Center.
If the Justice Department’s opinion remains in effect, he said, lawmakers may want to revisit the law and possibly strengthen the powers of inspectors general to report to Congress.
“Suddenly, all that is thrown into question,” Mr. Kostyack said. “The Justice Department didn’t show a lot of respect for the statutory role of the inspector general.”