A former member of the Benghazi committee has described the investigation as a “partisan” attempt to hamstring the ambitions of Hillary Clinton, confirming criticisms of the panel as a political instrument. Air Force Maj. Bradley Podliska, a self-described conservative Republican, told CNN the "partisan investigation" into attacks in Libya that killed four Americans shifted its focus almost entirely to former Secretary of State Hillary Clinton after revelations in March she had used a private email server in office.

Podliska, who was fired from the commission in June, said he resisted the panel’s shift. A lawsuit the former investigator plans to file alleges the committee “changed to focus on Secretary of State Hillary Clinton and the State Department, and de-emphasize the other agencies that were involved in the Benghazi attacks.”

“The victims' families are not going to get the truth and that's the most unfortunate thing about this,” Podliska told CNN.

The Select Committee on Benghazi, formed in May 2014, has spent $4.6 million in one of the longest-running congressional investigations in U.S. history, outlasting even the panel that investigated the Nixon administration's historic Watergate scandal.

Podliska’s comments follow heightened criticisms from congressional Democrats, who have characterized the panel as a baldly political gambit to sink Clinton, the frontrunner for the Democratic presidential nod.

Those concerns increased after House Majority Leader Kevin McCarthy made candid comments in recent interviews as to the political nature of the panel. “Everybody thought Hillary Clinton was unbeatable, right? But we put together a Benghazi special committee,” McCarthy told Fox News’ Sean Hannity Sept. 29.

“What are her numbers today? Her numbers are dropping,” McCarthy continued. “Why? Because she's untrustable. But no one would have known any of that had happened had we not fought.” The FBI opened an investigation into whether classified material may have been improperly transmitted on Clinton's private email server. 

Trey Gowdy, R-S.C., the Benghazi committee’s current chairman, has made similar admissions. On Fox News Sunday, the congressman was asked what Clinton’s emails had to do with the committee’s mandate.

“Well probably not much of anything,” Gowdy replied.

The attacks Sept. 11, 2012, killed Ambassador Christopher Stevens, fellow foreign service member Sean Smith, and CIA agents Tyrone Woods and Glen Doherty. Clinton later took responsibility for security measures that critics deemed irresponsibly lax.

Podliska, who said he plans to vote for the GOP presidential candidate in November 2016, said his decision to come forward arose as a matter of conscience. “I'm going up against powerful people in Washington. But at the end of the day I need to live with myself,” Podliska told CNN in an interview that will air on “State of the Union” Sunday.

The former investigator claimed his firing arose from his opposition to the commission’s tactics, as well as leave he had to take to fulfill his military obligations.

The committee strenuously rejected Major Podliska’s contentions. “We are confident that the facts and evidence give no support to the wild imagination fueling these and any future allegations, and the committee will vigorously defend itself against such allegations,” an unidentified spokesperson told CNN.