Updated: 10:25 a.m.

Sen. John McCain said today that the Justice Department should appoint a special counsel to investigate national security leaks in the White House.

Appearing on CNN’s “State of the Union,” the Arizona Republican said Attorney General Eric Holder’s appointment of two career prosecutors to probe the leaks was not enough.

He said he respects the two lawyers appointed but noted that the leak of Valerie Plame’s status as a CIA agent from the second Bush administration was investigated by a special counsel.

McCain also said Holder has “no credibility” with Congress because of his continued conflict with House Republicans over their investigation into the Fast and Furious gun scandal.

He suggested former Utah Sen. Bob Bennett (R) would be a good pick for special counsel.

McCain said he did not know whether President Barack Obama was personally involved in the leaks, but he said he should be held accountable regardless.

“The president may not have done it himself,” he said, “but the president is certainly responsible as commander in chief.”

Obama’s senior campaign adviser David Axelrod told ABC’s “This Week” that he was confident that an investigation would not reveal White House involvement in the leaks.

“We’ve been tougher on leaks than any administration in history,” he said. “We want to make sure that these missions are successful.”

Janie Lorber contributed to this report.