The war of words between the current and former White House administrations continues to escalate.
"I hate to say this, but he's a serial exaggerator," Karl Rove said in this latest installment, telling FOX News' "On The Record" that Vice President Joe Biden is spreading lies about his former boss.
"If I was being unkind I would say liar," Rove added."But it is a habit he ought to drop."
Rove's comments refer to an interview on CNN in which Biden boasted about taking the president down a peg over his leadership skills.
"I remember President Bush saying to me one time in the Oval Office," Biden said, "'Well, Joe,' he said, 'I'm a leader.' And I said: 'Mr. President, turn around and look behind you. No one is following.'"
Rove, who was Bush's top political adviser, said the exchange never happened. The man known as "Bush's Brain" also called Biden a “blowhard,” disputing the vice presidnent's previous claim that he had spent "a lot of hours alone" with Bush.
"Joe Biden was never alone with the president for more than few moments," Rove said. "There was staff in the room the whole time."
"It's his imagination; it's a made-up, fictional world. He ought to get out of it and get back to reality," Rove said. "He's making this up...You should not exaggerate and lie like this when you are the Vice President of the United States."
Biden's office declined to comment about the accusation.
During the segment, Rove challenged other claims made by the Vice President, including a story about coming under fire on a trip to Afghanistan.
Biden has been accused of exaggerating in the past, and in 1998 he dropped out of the presidential race after it was discovered that he plagiarized a speech from British Labor Party leader Neil Kinnock.
But Rove's comments are just the latest in a series of barbs traded between Bush staffers and current White House officials.
In the same CNN interview, Biden refuted statements made by former Vice President Dick Cheney about Americas safety. Cheney had said that the United States was less safe with Barack Obama as president. Biden called that claim "Dead Wrong."
Obama political adviser David Axelrod also made on the record comments about Cheney antagonistic statement.
“It’s a little incredible to me that he would argue somehow that what we’re doing in forging and international alliance to finally pursue a strategy to defeat and dismantle al Qaeda in Afghanistan is going to make us less safe,” Axelrod said on CNN's "State of the Union." “I think it was an unfortunate statement.”
While Rove and Cheney have jumped in an criticized the current White House, Bush, and his Secretary of State Condoleeza Rice have declined to comment on the current administration's agenda.
Bush said he that Obama "deserves his silence" and Axelrod commended the former president for acting like a statesman.