The oil saturating the Gulf spilled into Minnesota's political scene Friday when Michele Bachmann's DFL challenger announced an ad campaign targeting the congresswoman's comments on the disaster.

Bachmann is one of several members of Congress under fire this week for criticizing the Obama Administration's efforts to create a $20 billion BP escrow account settling claims from the oil spill.

State Sen. Tarryl Clark struck while the political iron was hot on Friday, launching a television ad that accuses Bachmann of siding with BP over the taxpayers. It is one of the most significant attacks Clark has made in the campaign so far – aided by the fact that her primary challenger, Maureen Reed, recently bowed out.

Clark spokester Carrie Lucking said the first ad will air at 10 p.m. Sunday on WCCO, with more to follow early next week. The ad buy is Clark's first in the Sixth District race.

Bachmann's comments trace back to early this week, when she called the escrow account "more of a redistribution of wealth fund" and warned BP not to be "chumps." The congresswoman changed her tone when the company voluntarily agreed to create the fund Wednesday, expressing skepticism over whether it could be administered properly by a political appointee.

Clark is expected to alert supporters to the ad, titled "Tender Mercies," requesting they give money specifically so the campaign can purchase television time. The total scope of the buy is reliant on how many much money is raised.

"America's worst-ever environmental disaster," an announcer says. "Killing thousands of jobs. Costing billions. It's BP's fault. And they should pay. But Michelle Bachmann calls making BP pay for the clean up 'extortion.' And said "If I was the head of BP, I would let the signal get out there – 'We're not going to be chumps.' If Bachmann lets BP off the hook, guess who's paying? Us. Michele Bachmann: standing up for BP. Not us."

Clark faces a decidedly uphill battle to win Bachmann's conservative district north of the Twin Cities, but she indicated in an interview that the BP comments may give her campaign added traction.

"This is a defining moment," Clark said in an interview Thursday. "This goes to the heart of what [Bachmann] really believes. She believes in no regulation. She believes in totally leaving hands off and then when there is a major crisis to start pointing blame. And I think it's a defining moment for her, I think it's a defining moment for the election and I think for voters it's a defining moment."

Minnesota GOP chair Tony Sutton responded to the ad Friday afternoon, calling it a "dishonest attack."

"Taxin' Tarryl Clark has no credibility when she says she is standing up for the Sixth Congressional District, and her new dishonest attack ad against Rep. Bachmann isn't going to fool anyone," Sutton said. "Michele Bachmann has consistently stated that those responsible should and will pay for the cleanup of the Gulf."

Update: Post has been updated to note that the first ad is running on Sunday.