Update: Ad details, and Rothfus’s campaign responds (below). According to the Rothfus campaign, SEIU is spending over $166,000 to air the spot on broadcast and cable TV in the Pittsburgh market from today through September 17.

One of the state’s largest labor unions is taking aim the top congressional challenger in Pennsylvania. SEIU will air a new television ad against Keith Rothfus, the Republican seeking to unseat Rep. Mark Critz.

It follows the release of two anti-Critz TV ads on Tuesday, one by Rothfus, one by the National Republican Congressional Committee.

The ad features testimonials from regular-seeming people and is heavy on charged class language. It seeks to cast Rothfus, an attorney from Allegheny County, as an outsider.

“Keith Rothfus. He’s for millionaires, not people like us,” says a woman to the camera.

“He should be more concerned with Pennsylvania working families than millionaires,” says an older man. “And Seniors should be able to count on their Medicare.”

“I need my Medicare,” an older woman says angrily to camera.

In an accompanying press release, SEIU Local 668 President Kathy Jellison continued the theme.

“Wall Street lawyer Keith Rothfus is a candidate of the 1% of America, the millionaires and billionaires, not the rest of us,” he said.

“Talk about ‘not on our side’,” responded NRCC spokesman Nat Sillin, “Mark Critz supports gutting over $700 billion from seniors’ Medicare to pay for ObamaCare.  It’s unsurprising Critz has his attack dogs trying to divert attention from his record of  voting to support President Obama nearly 70% of the time and voting to support ObamaCare 20 times.”

Update: Rothfus Campaign Manager Jon Raso said the ad buy was Washington DC Dems’ reward for Critz’s voting record.

“Now that Congressman Critz has supported the agenda of the far-left SEIU leadership and President Obama, they’re returning the favor too,” Raso said. “We do not need any more evidence to tell us just how out of touch Congressman Critz really is with Southwestern Pennsylvania; the special-interest help from the far-left will not save his failed political career.”

PoliticsPA is seeking comment from the Rothfus campaign.

The bases for the charges are familiar: Rothfus’s signature on the Americans for Tax Reform no tax pledge and his support for a plan by Rep. Paul Ryan (R-WI) to reform Medicare.

The Ryan plan is a favorite target for Democrats and their allies, who say that it would result in higher out of pocket expenses for seniors and result in a lower quality of care.

Supporters of the plan note that Medicare in its current form is headed toward bankruptcy, and say that it would impact Americans 55 years-old or older.

The political arm of the Service Employees International Union (SEIU-COPE) has actively supported Critz since the Democratic primary. Fellow Rep. Jason Altmire alienated the labor group with his vote against the Affordable Care Act. Critz, on the other hand, wasn’t yet in office. Since his election, Critz has sought to walk a delicate balance between opposing individual provisions of the law while also opposing efforts to repeal the bill as a whole.