WASHINGTON — A coalition of government watchdogs assailed the Justice Department for temporarily blocking a whistleblower's complaint against President Donald Trump from being transmitted to Congress, saying in a letter this week that its actions could deter individuals from reporting government abuse.

The six-page letter, signed by the Justice Department's own inspector general and about five dozen counterparts from other federal agencies, is a remarkable rebuke of the agency, which argued that the whistleblower's allegations of foreign election interference were not an "urgent concern."

The group, headed by Justice Department Inspector General Michael Horowitz, took issue with an opinion by the agency's Office of Legal Counsel. The opinion overruled a determination by the intelligence community's own watchdog that the whistleblower's allegations, which have since sparked an impeachment inquiry, appeared credible and, therefore, should be brought to Congress.

The Council of the Inspectors General on Integrity and Efficiency said the opinion, "if not withdrawn or modified, could seriously undermine the critical role whistleblowers play in coming forward to report waste, fraud, abuse, and misconduct across the federal government."

"Whistleblowers play an essential public service in coming forward with such information, and they should never suffer reprisal or even the threat of reprisal from doing so," the letter says. "We believe that the ... opinion creates uncertainty for federal employees and contractors across government about the scope of the whistleblower protections, thereby chilling whistleblower disclosures.”

Assistant Attorney General Steven Engel said in a five-page response Friday that the group's concerns "reflect certain misconceptions about the opinion."

"Our opinion did not interpret any of the statutory provisions protecting whistleblowers from retaliation, and nothing in our opinion alters the protections that Congress has provided," wrote Engel, who's in charge of the Office of Legal Counsel.

Instead, he wrote, the opinion concluded that the whistleblower's allegations against Trump did not involve activities related to the intelligence community.

"Simply put: The President is not part of the intelligence community as Congress defined it," Engel wrote.

The whistleblower, an employee within the intelligence community, alleged in a complaint that White House officials had expressed concerns that Trump sought to pressure his Ukrainian counterpart to pursue an investigation against his potential presidential rival, former Vice President Joe Biden. In late August, Michael Atkinson, the inspector general of the intelligence community, forwarded the complaint to the acting director of National Intelligence, concluding that such a request could be viewed as soliciting a foreign power's help, a violation of campaign finance laws.

But Joseph Maguire, the acting director of national intelligence, delayed providing the whistleblower's complaint to Congress, saying executive privilege protected the confidentiality of communications with Trump.

"This case was unique and unprecedented," Maguire told the House Intelligence Committee in late September. "The White House did not direct me to withhold the complaint."

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Contrary to Atkinson's finding, the Justice Department's legal counsel concluded that the whistleblower's allegations did not meet the statutory definition of "urgent concern" because it does not involve "funding, administration, or operation of an intelligence activity."

Engel, the assistant attorney general, reiterated this point in his letter, saying Trump's conversation with the Ukrainian president, as described in the whistleblower's complaint, did not relate to any intelligence activity.

"To the contrary, the information in the complaint appears to have been derived from the complainant's conversations with White House officials and from press accounts, not from any intelligence community operation," Engel wrote.

But the inspectors general group said in its letter that the Justice Department's narrow interpretation of what qualifies as an "urgent concern" — and therefore must be reported to Congress — raises questions about whether the whistleblower is entitled to protections against retaliation. Those concerns extend to other government employees and contractors who may no longer believe it's worth the risk to expose what they believe to be government misconduct, the group said.

"That would be a grave loss for the (inspectors' general) oversight and, as a result, for the American taxpayer," the letter says, adding that inspectors general have historically relied on whistleblowers to conduct nonpartisan oversight of federal agencies.

In response, Engel said the Justice Department's opinion "in no way diminishes the robust protections" afforded by Congress to whistleblowers.

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The whistleblower named Rudy Giuliani, Trump's personal lawyer, and Attorney General William Barr, as among those involved in the effort to urge Ukraine to investigate Biden.

"I will have Mr. Giuliani to give you a call, and I am also going to have Attorney General Barr call and we will get to the bottom of it," Trump said in a 30-minute phone call last July with Ukraine President Volodymyr Zelensky.

The Justice Department has maintained that Barr knew nothing about Trump's efforts to enlist his help until weeks later and didn't communicate with Ukraine officials.

The letter comes amid a fast-moving impeachment inquiry that has now involved damning testimonies from American diplomats.

William Taylor, the top American diplomat in Ukraine, testified this week that the White House withheld critical military aid as part of an effort to pressure the country to open an investigation into Biden and the energy company that employed the former vice president's son.

Contributing: Bart Jansen and David Jackson