Great American Alliance, a group that supports President Trump, released a video critical of former FBI Director James Comey on Tuesday, two days before he testifies in an open session before the Senate Intelligence Committee.

The ad titled "Showboat" accuses Comey of "putting politics over protecting America" and "being consumed with election meddling" last year.

Comey's testimony on Thursday will be his first public appearance since Mr. Trump fired him early May.

He will likely face tough questions related to the Russia investigation and his conversations with Mr. Trump.

According to a Great American Alliance press release, the 30-second video will move to national television on Thursday as coverage of Comey's testimony surfaces. The ad will also play during the hearing, the statement reads.

The ad will play on Fox News and CNN, according to the Associated Press. And it will be officially released online on Wednesday.

In the ad, a woman's voice lists what are labeled as shortcomings of Comey and couples them with headlines from news outlets such as CNN, USA Today, American Spectator, AlternNet and conservative website Breitbart, run formerly by Mr. Trump's key adviser Steve Bannon.

"After he testified before the U.S. Senate, Comey's own staff admitted some of his answers were flat out wrong," the narrator says.

"After the FBI banned terms like radical Islam for political correctness, Comey allowed the dangerous practice to continue," she adds. "When terror attacks were on the rise last year, Comey was consumed with election meddling."

The narrator concludes, "James Comey. Just another D.C. insider only in it for himself."

In the press release, conservative commentator Tomi Lahren, who joined Great American Alliance in May after a fall-out with Glenn Beck's The Blaze, promoted the ad.

"The Establishment has done nothing but beat a war drum for the last year. Meanwhile, we've been focused on making America great for all the hard-working folks who put their faith in Donald Trump," Lahren said. "It's a shame we must devote time and attention to D.C. Insider James Comey, but it's important to set the record straight in advance of and during his testimony."

The Great American Alliance is an arm of the Great American PAC, a political action committee that helped raise $30 million for Mr. Trump's successful presidential bid, according to the group.