It's not every day that a House Republican charges that the powerful U.S. Chamber of Commerce is "in the pocket of Communist China."

But Michigan freshman Rep. Kerry Bentivolio did just that on Thursday when he announced he would return the Spirit of Enterprise Award he received from the group earlier this Congress.

“It is with great pride that I reject their award, and call on them to stand on the side of America, instead of on the side of China and corporate interests seeking to exploit people for profit,” Bentivolio said in a press release.

Rep. Kerry Bentivolio announced he would return the Spirit of Enterprise Award he received from the U.S. Chamber of Commerce. (Courtesy Photo)

His chief of staff, Rob Wasinger, gave more detail on the decision.

"The U.S. Chamber is in the pocket of Communist China and big companies seeking cheap labor in the United States," Wasinger said in the release. “We think it is morally repugnant for the chamber to pursue, as a matter of public policy, initiatives which exploit the poor and oppressed, just so they can keep labor costs down for their Fortune 500 member companies.”

Wasinger told the Washington Examiner that the Chamber's stance on immigration reform is part of the reason for the timing of the award's return. The Chamber gives out the award annually, and Bentivolio received it in March along with 205 other House members.

"In the past two months, the Chamber has made it clear that it is mostly interested in promoting and passing legislation granting amnesty to millions of illegal aliens,” he said.

The U.S. Chamber of Commerce endorsed Bentivolio's primary challenger, attorney Dave Trott, in May. The Michigan Chamber of Commerce has also endorsed Trott. Mitt Romney has endorsed Trott as well.

Bentivolio is widely viewed as one of this cycle's most vulnerable incumbents. It's an inversion of the usual narrative, as the Chamber typically invests in defending established incumbents from Tea Party primary challengers.