A Democratic super PAC is taking to the airwaves with a TV ad attacking former governor Mark Sanford (R) in South Carolina's 1st district special election, marking the first time an outside group has gone on the air in the race between Sanford and Democrat Elizabeth Colbert Busch.

The narrator of the House Majority PAC ad hits Sanford for what she calls his "taxpayer-fueled spending spree."

"He charged us $400,000 to travel around the world to France, China and Argentina," the narrator continues.

When Sanford was governor, the South Carolina Ethics Commission charged that he broke the law when he flew business or first class while on state business overseas and used state aircraft for personal travel. Sanford paid a $74,000 fine, though he maintains he never broke the law.

Law enforcement officials concluded in 2009 that Sanford did not improperly use state money to pay for trips to New York and South America to see his Argentinian mistress. The governor disappeared from the state for nearly a week that year before disclosing his extramarital affair. He is now engaged to the Argentinian woman.

The Democratic group is spending in the $400,000-$600,000 range to air the spot.

The buy comes as Sanford has taken to the airwaves with his first general election ad, a spot that attacks Colbert Busch for taking money from labor unions. The Hotline reports that Sanford is spending just under $100,000 to air the ad.

It also comes amid a revelation that Sanford's ex-wife filed a trespassing complaint  against the former governor, which he called an "unfortunate reality" of divorce.

The special election is May 7. The two candidates have agreed to debate on April 29.