The Senate Judiciary Committee chairman promised to call four signers of the Foreign Intelligence Surveillance Act warrants targeting Carter Page to testify in the wake of the Justice Department watchdog’s report on FISA abuse.

Sen. Lindsey Graham of South Carolina told CBS News that he would seek private depositions and public testimony from former FBI Director James Comey, former FBI Deputy Director Andrew McCabe, former Deputy Attorney General Sally Yates, and former Deputy Attorney General Rod Rosenstein.

The Republican committee leader also plans to call current FBI Director Christopher Wray, who took over the bureau after Comey was fired in 2017 and wasn’t involved in approving FISA applications on former Trump associate Page.

Graham told CBS’s Catherine Herridge he planned to deliver a witness list for the FISA hearings to the Justice Department shortly and indicated weeks of FISA witness hearings might begin as soon as late February or early March.

“What I will do is I will get to the bottom of how the FISA warrant system failed and make sure we reform it, and it doesn't happen again,” Graham told Margaret Brennan on Face the Nation on Sunday.

The DOJ Inspector General Michael Horowitz’s December report on FISA abuse concluded that the FBI’s investigation was filled with serious missteps and concealed exculpatory information from the Foreign Intelligence Surveillance Court. Horowitz said at least 17 "significant errors and omissions" were discovered in the Page FISA applications spanning from fall 2016 to summer 2017.

The FISA filings relied upon a salacious and unverified dossier compiled by British ex-spy Christopher Steele, who’d been hired by Fusion GPS, which in turn was hired by the Hillary Clinton campaign and the Democratic National Committee through the Perkins Coie law firm.

Wray, who called the FISA findings “utterly unacceptable” during House testimony last week, concurred with the DOJ’s conclusions that at least two of the four FISA warrants against Page amounted to illegal surveillance. Wray said the bureau was working to “claw back” any intelligence gleaned through the Page FISAs.

A total of four FISA applications and renewals against Page were signed off on by FBI and DOJ leadership and approved by the FISA court.

The FBI's Comey and the DOJ's Yates greenlighted the initial October 2016 FISA application as well as the January 2017 FISA warrant renewal.

Comey signed the April 2017 FISA renewal for the FBI. The DOJ’s signatory that time was Dana Boente, who was the acting attorney general following Yates's firing in late January 2017 and then-Attorney General Jeff Sessions's recusal from Russia-related investigative matters.

Yates tweeted “to the career men and women of DOJ” this week that “you are both the backbone and the heart of the Department.” He tweeted that “your noble dedication to the rule of law is the foundation of our republic” in the wake of the DOJ reversing its prison sentence recommendation for Trump associate Roger Stone.

Boente is the only signatory remaining in active government service — Wray picked him to be the FBI’s general counsel in January 2018. Boente replaced Jim Baker, who has said he was personally involved in the approval of at least the first FISA warrant against Page and who repeatedly defended the FBI’s handling of the Steele dossier.

Graham did not say he planned to call Boente or Baker.

McCabe approved the fourth and final FISA warrant for the FBI in June 2017 after Comey was fired that May. McCabe himself was fired in March 2018 after Horowitz concluded he “lacked candor” with investigators. The U.S. Attorney’s Office in Washington, D.C., also handling Stone’s case, was weighing criminal charges against McCabe, but informed McCabe on Friday that "the government has decided not to pursue criminal charges" and that "we consider the matter closed." McCabe previously sued the FBI and the DOJ, claiming wrongful termination.

Rosenstein, whose memo on Comey was used by President Trump to justify Comey’s firing and who appointed special counsel Robert Mueller in May 2017, signed off on the June 2017 FISA request for the DOJ.

Comey tweeted this week that the Stone saga “is dangerous territory for the rule of law.”

Horowitz previously condemned Comey for the “unauthorized disclosure of sensitive investigative information … in order to achieve a personally desired outcome” when he leaked his memos to prompt a special counsel.

“Certain former FBI employees who agreed to interviews, including Comey and Baker, chose not to request that their security clearances be reinstated for their OIG interviews,” Horowitz’s FISA report noted. “Therefore, we were unable to provide classified information or documents to them during their interviews to develop their testimony, or to assist their recollections of relevant events.”

When asked about Graham’s plans for the FISA witnesses, his communications director, Kevin Bishop, told the Washington Examiner: “Stay tuned!”