U.S. Attorney John Durham risks bad press the longer it takes him to decide whether to file any charges in his review of the Russia investigation, according to a former federal prosecutor.

Andrew McCarthy, a former chief assistant U.S. attorney in New York and senior fellow at the National Review Institute, also warned the investigation will go "down the memory hole" if President Trump does not win reelection in November during an interview on Saturday.

Radio host Steve Malzberg asked McCarthy to respond to Attorney General William Barr's recent interview with Fox News's Laura Ingraham, in which he offered some insight into the so-called "investigation of the investigators" and said there appeared to be a "pattern of events" in which officials sought to "sabotage" Trump's presidency.

“My own view is that the evidence shows that we’re not dealing with just mistakes or sloppiness," the attorney general said in that interview. "There is something far more troubling here, and we’re going to get to the bottom of it. And if people broke the law, and we can establish that with the evidence, they will be prosecuted."

McCarthy said it was "important" that Barr reminded people that Durham is looking into possible misconduct by federal law enforcement and intelligence officials in a "very serious way."

"I think just as a matter of common sense if you're Durham, and we don't know what his timeline is, but to make a decision one way or another," he added. "But the closer it gets to Election Day, the more any charges he brought would be framed by the media as kind of a Trump campaign stunt," McCarthy said.

Durham, the top federal prosecutor in Connecticut, was appointed last year by Barr to investigate the Trump-Russia investigation and to review possible misconduct by federal law enforcement and intelligence officials. The review upgraded into a criminal investigation in the fall, giving the prosecutor the power to impanel a grand jury and hand down indictments, and is expected to wrap up sometime in the summer. It was recently revealed that Durham drove to Washington, D.C., to make sure the investigation stayed on track during the coronavirus outbreak and is increasingly focused on former CIA Director John Brennan.

At least one former FBI lawyer, Kevin Clinesmith, is under criminal investigation after the Justice Department inspector general found he altered a document in a filing for a Foreign Intelligence Surveillance Act warrant to wiretap onetime Trump campaign adviser Carter Page.

McCarthy said he believes there was "appalling misconduct," but noted he knows Durham faces a tough challenge in making any criminal cases.

While the president and his allies have championed the investigation, Democrats have criticized Durham's review as a politically-motivated scheme to undermine the work of special counsel Robert Mueller and attack Trump's perceived enemies.