On Feb. 20, nearly 7,000 probationary employees at the Internal Revenue Service began receiving an unsigned letter telling them that they had been fired for poor performance.

Trump administration lawyers insist that the IRS and other federal agencies have acted within their authority when they ordered waves of mass terminations since Trump took office. But according to previously unreported emails obtained by ProPublica, a top lawyer at the IRS warned administration officials that the performance-related language in his agency’s termination letter was “a false statement” that amounted to “fraud” if the agency kept the language in the letter.

The emails reveal that in the hours before the IRS sent out its Feb. 20 termination letter, a fierce dispute played out at the agency’s highest levels.

Joseph Rillotta, a senior IRS lawyer, wrote that “no one” at the IRS had taken into account the performance of the probationary workers set to be fired. Rillotta urged that the language be struck from the draft termination letter.

If the falsehood wasn’t removed, Rillotta said he would file a report with the inspector general for the IRS.

No one appeared to respond to Rillotta’s first email. In a follow-up email, he said he was “pleading with you to remove the clause,” adding: “It is not an immaterial false statement, because it is designed to improve the government’s posture in litigation (to the detriment of the employees that we are terminating today).”

Because it was not true, he wrote, “That renders it, as I see it, an anticipatory fraud on tribunals of jurisdiction over these employment actions.”

Rillotta was again ignored. The IRS sent out the Feb. 20 termination notice with the disputed language in it, according to copies received by fired workers who shared them with ProPublica. The notice said the decision to fire the workers had taken “into account your performance” as well as administration guidance and “current mission needs.”

In fact, many of the employees had received laudatory reviews with no hint of any concerns.

Soon afterward, the inspector general for the IRS took preliminary steps to look into the matter, according to a person familiar with the effort who wasn’t authorized to speak with reporters. This person said they told the investigator that they agreed with Rillotta that the performance rationale was false.

Michelle Bercovici, a lawyer who represents federal workers, told ProPublica that Rillotta’s ignored warnings should make it easier for plaintiffs to show that the mass firings were “arbitrary and capricious,” the legal standard needed to invalidate a federal agency’s action. She added that the emails could also help plaintiffs recover attorneys’ fees from the government.

“When an agency acts based on false information, not only does it set the action up for being overturned,” she said. “It also means the agency is not going to have many defenses to its actions and could be liable for fees.”

Spokespeople for the Treasury Department and IRS did not respond to requests for comment. An Office of Personnel Management spokesperson referred ProPublica to a revised memorandum stating that OPM “is not directing agencies to take any specific performance-based actions regarding probationary employees.”

The terminations at the tax agency were among the deep cuts to federal agencies by the Trump administration and its Department of Government Efficiency, led by the billionaire Trump adviser Elon Musk.

Multiple federal lawsuits are now challenging the Trump administration’s mass firings. Last week, two federal judges temporarily blocked the IRS and other firings, but the lawsuits continue.

The issue of whether the performance rationale was legitimate has been central to the suits. One suit, brought by a group of labor unions, advocacy groups and other parties in California federal court, alleges that OPM directed the probationary firings and so “perpetrated one of the most massive employment frauds in the history of this country, telling tens of thousands of workers that they are being fired for performance reasons, when they most certainly were not.”

In response, administration lawyers deniedthat OPM directed agencies to fire probationary workers based on performance or misconduct. Instead, the filing says, “OPM reminded agencies of the importance of the probationary period in evaluating applicants’ continued employment and directed agencies to identify all employees on probationary periods and promptly determine whether those employees should be retained at the agency.”

The plaintiffs later expanded that suit to include the Treasury Department, which oversees the IRS, as one of the defendants. In mid-March, Judge William Alsup issued a preliminary injunction in the case, saying the administration’s probationary firings were based on “a lie.” Alsup ordered several federal agencies, including the Treasury, to reinstate thousands of fired employees. The Trump administration has appealed Alsup’s ruling.

Another suit, filed in Maryland federal court by nearly two dozen Democratic state attorneys general, also claims that the IRS mass firings were unlawful and should be reversed. (In that case, administration lawyers asserted that the mass firings were lawful.)

Court filings in both cases have partially revealed how the administration chose to make the legally questionable decision to fire probationary workers en masse on performance grounds..

At the IRS, the plan to fire probationary employees began in early February, according to an affidavit filed in the Maryland case.

A high-ranking Treasury Department official instructed a senior IRS personnel employee named Traci DiMartini to identify all probationary IRS employees and fire them “based on performance,” according to an affidavit DiMartini later filed in court.

DiMartini had “never heard of mass probationary employee firings,” she stated in her affidavit.

When DiMartini asked the Treasury Department official why they were firing so many probationary employees, she was told that the order came from OPM, which was staffed by Trump appointees and members of DOGE.

In her affidavit, DiMartini confirmed what Rillotta wrote in his emails — that it was false to say probationary employees were fired for performance. DiMartini’s office “did not review or consider” any probationary employees’ job performance or conduct. Nor did the Treasury Department. “I know this because this fact was discussed openly in meetings,” DiMartini stated in her affidavit.

According to DiMartini’s affidavit, OPM drafted the IRS mass-termination letter. While Treasury officials made several changes to it, the IRS’s personnel office where DiMartini worked “was not permitted to make any changes to the letter,” DiMartini’s affidavit said.

DiMartini refused to sign the mass-termination letter, according to her affidavit. The then-acting commissioner of the IRS, Douglas O’Donnell, also refused to sign the letter.

When thousands of affected IRS employees finally received the letter, it arrived from a generic email account. No agency official’s name appeared anywhere in the document.