While Democratic Gov. Maggie Hassan waits on the sidelines, allies in Washington are not waiting to get involved in what is shaping up to be a hotly contested re-election contest for Republican Sen. Kelly Ayotte.

On Wednesday, the Democrat-supporting Senate Majority PAC released a new television commercial that seeks to combat ads released last month by Americans for Prosperity. A source that tracks campaign ads said the group spent $250,000 on its buy.

“Fifteen months before the election, yet the out-of-state, oil billionaire Koch brothers have already spent $1.2 million in New Hampshire to keep Kelly Ayotte in the U.S. Senate,” says the ad, taking aim of her support for tax breaks for oil companies. “With the Koch Brothers and Kelly Ayotte busy helping each other, who’s helping New Hampshire families get ahead?”

While Hassan has yet to announce her candidacy, a poll released earlier this month by Public Policy Polling, a Democratic-leaning firm, showed Hassan with a slim lead over Ayotte, a freshman senator, and a larger one among women voters.

Jennifer Horn, chairman of the New Hampshire Republican State Committee, sent an email to supporters Tuesday afternoon in advance of the ad’s release seeking fundraising support.

“Disgraced former Senate Majority Leader Harry Reid will do anything to reclaim his lost majority,” she wrote. “Governor Hassan has all but announced her Senate candidacy to help Harry Reid and Washington Democrats do Barack Obama’s bidding.”

Earlier this year, the Senate Majority PAC also launched a digital ad campaign accusing Ayotte of being aligned closely with special interests.

The Rothenberg & Gonzales Political Report/Roll Call rates the New Hampshire race as Leans Republican.