The Obama campaign has defended the commercials, pointing to new reports that indicate Romney continued to be listed as Bain's president and CEO after 1999 and served on the corporate board of at least one Bain investment after that time.

"Romney has said he had no authority or responsibility for managing Bain since February 1999, but that has been proven false. He remained CEO, President, Chairman, sole owner and sole shareholder through 2001," said Obama spokesman Ben LaBolt in a statement Thursday. "Governor Romney either misled the American people about when he left Bain or misled the [Securities and Exchange Commission]. Which one is it? The Romney campaign still won’t say.”

And on Friday, the campaign mocked McDonnell for declaring the "central premise of Romney's candidacy off limits" in an email to reporters.

But the Romney campaign and Bain Capital have argued that there is no evidence that the former Massachusetts governor was actively involved in the management of Bain during that period, during which he was running the Salt Lake City Olympic games.

"As Bain Capital has said, as Governor Romney has said, and as has been confirmed by independent fact checkers multiple times, Governor Romney left Bain Capital in February of 1999 to run the Olympics and had no input on investments or management of companies after that point," said Romney spokeswoman Andrea Saul in a statement Thursday.

Romney also released a pair of commercials, set to air in Virginia, blasting the Obama campaign as deceitful in their attacks. The president is scheduled to campaign in the pivotal swing state Friday and Saturday.