A GOP outside group has started attacking Rep. Collin C. Peterson of Minnesota on the airwaves — less than two weeks after a local Republican state lawmaker announced he would challenge the longtime Democrat in 2014.

The ad, released by the American Future Fund, accuses the 12-term Democrat of “losing his Minnesota nice” after being in Washington, D.C., too long.

“He’s been in Washington for decades and the choices he makes affect our lives. So where is he when we want answers?” says the announcer in the 30-second spot. “… Tell Collin Peterson if he’s lost his Minnesota nice he’s been in Washington too long.”

The ad is backed by a nearly $100,000 buy on broadcast and cable in the 7th District, which spans the western third of the state.

Peterson is a top GOP target in 2014. GOP presidential nominee Mitt Romney carried the 7th District with a 10-point margin last cycle.

Two weeks ago, state Sen. Torrey Westrom became the first Republican to announce a challenge to Peterson. GOP businessman Scott Van Binsbergen is also eyeing a bid but has yet to make a decision on the race.