U.S. Sen. John McCain and his primary rival, former Congressman J.D. Hayworth, accused each other of being consummate Washington insiders Tuesday.

The accusations followed new McCain radio and television ads blasting Hayworth’s stint as a D.C. lobbyist in 2008, when he lobbied Congress on tax issues.

On the television ad, a male voice says, “J.D. Hayworth says he’s an outsider. But after he was voted out of Congress he became a registered lobbyist. Hayworth was paid thousands by a Florida corporation to lobby the very committee he used to serve on. Outsider? A lobbyist is as inside Washington as it gets.”

McCain’s communications director, Brian Rogers, said it was “stunning” that Hayworth would register as a lobbyist given that he was voted out of office in part because of his connections to convicted lobbyist Jack Abramoff.

Hayworth was the subject of an investigation into Abramoff’s dealings and failed to report the use of the lobbyist’s skyboxes for fundraising activities. While he racked up considerable legal fees in connection with the probe by the U.S. Department of Justice, Hayworth was never charged and says Abramoff never lobbied him directly on any issue.

Registration forms indicate Hayworth registered one month after his one-year lobbying ban as a former member of Congress was lifted. He earned $10,000 in 2008 lobbying for an estate planning firm.

Hayworth’s spokesman, Mark Sanders, responded, “‘This is fun with partial facts day’ in McCain world.” He continued, saying McCain began his career in Washington as a lobbyist in 1976 as the Navy’s liaison to the Senate.

He also noted several key McCain staffers and campaign advisers — including Rick Davis, Charles Black and Mark Buse — are themselves current or former lobbyists. “This is just another effort on his part to remake himself during this campaign by spinning half-truths and flip-flopping on important issues.”

McCain’s camp, meanwhile, shot back that Hayworth’s attempt to draw a parallel with McCain’s service as a Navy liaison was absurd and offensive.

“It is beyond the pale for Congressman Hayworth to compare his time lobbying his former House colleagues for some special deal on behalf of a Florida company to Senator McCain’s honorable service in the United States Navy,” Rogers said, adding the response was a sign of desperation and indicating Hayworth “should know the difference between serving our country in uniform and profiting from the special interests as a Washington lobbyist.”