– The Justice Department has already summoned hundreds of government officials for interviews in its investigation of national security leaks, meaning that the investigation is already well underway, according to Senate Intelligence Committee Chairwoman Dianne Feinstein (D-CA).

“We are three weeks into the investigation by the two prosecutors. Literally hundreds of people have been summoned for interviews,” Feinstein said in a short interview Tuesday. “So the process has begun and my view is that the process should be allowed to run.”

Feinstein was responding to calls from several GOP senators for an independent special counsel to investigate recent leaks into classified national security program. Thirty-one GOP senators wrote a letter to Attorney General Eric Holder calling for an independent counsel Tuesday.

The letter was led by Sen. Lindsey Graham (SC) and signed by Sens. Lamar Alexander (TN), Kelly Ayotte (NH), John Barrasso (WY), Roy Blunt (MO), John Boozman (AR), Richard Burr (NC), Saxby Chambliss (GA), Susan Collins (ME), John Cornyn (TX), Mike Crapo (ID), Jim DeMint (SC), Mike Enzi (WY), Charles Grassley (IA), John Hoeven (ND), Mike Johanns (NE), Mark Kirk (IL), Mitch McConnell (KY), John McCain (AZ), Jerry Moran (KS), Lisa Murkowski (AK), Rand Paul (KY), Rob Portman (OH), James Risch (ID), Pat Roberts (KS), Marco Rubio (FL), Jeff Sessions (AL), John Thune (SD), Pat Toomey (PA), David Vitter (LA), and Roger Wicker (MS).

Feinstein said that if the current process proves ineffective, she would reconsider. She also said that despite reports Tuesday the Defense Department was the subject of the investigation, her information is that the investigation is looking into the actions of officials throughout the executive branch.

“My understanding is that many dozens of FBI personnel have been asked to come in for interviews. I think it is a robust investigation and that’s what we want,” she said. “A special counsel takes four or five months to get set up and hire staff and become functioning. This is already functioning and has been for three weeks.”

In a short interview, Graham rejected that argument and promised to push not only for an independent investigation but one that is expanded to cover more leaks over a greater period of time.

“I cannot believe this is good policy to allow an administration to investigate itself,” he said. “[Feinstein] was OK with an independent counsel to investigate [lobbyist Jack] Abramoff and [former CIA case officer] Valerie Plame because the argument was the Bush administration was too tied to the suspected wrongdoing. I can assure you I’m not going to let this go.”

Graham called for a special counsel that senators could support, and said that there are Democrats he might endorse for the role but that he won’t accept the two Justice Department officials chosen by Holder .

Graham also called for the investigation to be expanded well beyond the two leaks that he said are the subjects of the investigation: U.S. involvement in the Stuxnet virus that disabled Iranian nuclear centrifuges and the details of a foiled airplane bomb plot originating out of Yemen.

He said the investigation should include the leaks of details of the May 2011 raid in Abbotabad that resulted in the killing of al Qaeda leader Osama bin Laden, the disclosures of secret U.S. bases in Africa and a secret U.S. drone base in Pakistan, the disclosure of the process the president uses to compile his “kill list,” and disclosures of details of negotiations between the U.S. and the Taliban over a prisoner swap for Army private Bowe Bergdahl.

The Cable pointed out that two of those leaks were disclosed publicly by Feinstein herself. She disclosed the existence of the Pakistan drone base in an open hearing in 2009 and disclosed the details of the Taliban negotiations in a March interview with The Cable.

“My beef is not with Senator Feinstein. My beef is with a system that’s failing,” Graham said. “I think that this failure is politically motivated. The leaks have tried to create a political advantage for this president. Nothing Senator Feinstein has done or said has been in that mode.”

Feinstein’s leaks may have been accidental and her disclosures about negotiations with the Taliban didn’t actually compromise any counterterrorism operations in the field, so the investigation should be limited to the actions of administration officials, Graham said.

“This is part of a plan to compromise our programs for political purposes, in my view. That’s the allegation I’m making,” he said.