Attorneys for former special counsel Jack Smith, who brought criminal charges against President Trump, denounced a watchdog investigation into Smith’s work as “imaginary and unfounded” in a letter to the Office of Special Counsel.

The letter, obtained by The Associated Press on Tuesday, marked Smith’s first response to news that the government watchdog was investigating Smith for potential violations of the Hatch Act, which prohibits government employees from engaging in political activity.

Trump allies have accused the Biden-era special counsel of pursuing criminal charges against Trump in an effort to thwart his White House bid. Former Attorney General Merrick Garland tapped Smith in 2022, three days before Trump launched his 2024 campaign.

In their letter to acting head of the Office of Special Counsel, Jamieson Greer, attorneys Lanny Breuer and Peter Koski said the investigation into Smith’s prosecutions of Trump is “wholly without merit.”

“Mr. Smith’s actions as Special Counsel were consistent with the decisions of a prosecutor who has devoted his career to following the facts and the law, without fear or favor and without regard for the political consequences, not because of them,” the lawyers wrote.

Sen. Tom Cotton (R-Ark.) requested the watchdog investigation, alleging Smith sought to interfere in the election by trying to fast-track cases, pointing to one instance when he asked the Supreme Court to rule on an issue before a lower court.

But Smith’s attorneys pushed back on that argument, insisting he made no decisions with an eye toward the election.

“A review of the record and procedural history demonstrates the opposite — Mr. Smith was fiercely committed to making prosecutorial decisions based solely on the evidence, he steadfastly followed applicable Department of Justice guidelines and the Principles of Federal Prosecution, and he did not let the pending election influence his investigative or prosecutorial decision-making,” Smith’s lawyers wrote.

“The predicate for this investigation,” the lawyers added, “is imaginary and unfounded.”

Smith brought criminal charges against the president in two distinct cases: one over the president’s efforts to stay in power after losing the 2020 election, and another over his mishandling of classified documents and his refusal to comply with requests for their return.

Both cases were dropped before Trump took office in January.

The Associated Press contributed.