General Motors and Ford appear to be at odds over the use of Chinese battery technology in electric cars. 

GM CEO Mary Barra and her team warned members of Congress in June that Ford's use of the technology could pave the way for China to dominate US car manufacturing, the Wall Street Journal reported. 

GM's apparent rebuke of Ford's strategy came after Ford Motor CEO Jim Farley had earlier told the lawmakers that using the technology would give the US a leg up in its EV battle with China.

The battle should matter to anyone in the market for EVs. 

Starting next year, buyers won't be able to claim a $7,500 tax credit on electric cars if they contain battery parts from what the US considers a "foreign entity of concern."

It's not clear yet whether that means Ford's use of Chinese battery tech will disqualify some of its cars. But it would certainly be an advantage for GM if it did, because it would make their EVs considerably cheaper than Ford's.

President Biden will eventually determine the rules of the tax credit and what's considered a foreign entity. 

Ford, for its part, is adamant that using Chinese tech shouldn't disqualify its cars. 

"It would be absurd to classify Ford or its fully owned subsidiary as a foreign entity, much less one of concern. We're Ford, and we're all-in on America," Chris Smith, Ford's chief government affairs officer, told the Journal. 

A GM spokesperson, meanwhile, suggested the company wasn't trying to pick a fight with its cross-town rival, telling the Journal: "This is not about GM vs. Ford."

Ford and GM didn't immediately respond to requests for comment.

Ford halted construction on a new battery plant in Michigan this week as Republican lawmakers apply more scrutiny to the company's ties to a Chinese battery maker. When Ford announced the $3.5 billion EV battery plant earlier this year, the company said it would be contracting battery technology from China's Contemporary Amperex Technology Co. Ltd., or CATL.

Ford has insisted that the plant with CATL, which it said would create 2,500 new jobs in the area, will be "built and run by a wholly owned Ford subsidiary." The company said the decision to pause construction came as Ford assessed whether they could "competitively operate the plant," Ford Spokesman T.R. Reid told Bloomberg.

The decision to pause construction in Marshall, Michigan, earlier this week drew the ire of United Auto Workers President Shawn Fain, who is currently leading unionized workers at all three Detroit automakers on a historic strike.

"The Marshall threat, as I like to call it, is just more of the same from the companies," Fain told reporters after a Tuesday visit from President Biden at a GM picket line in Michigan. "All the workers are asking for is their share of dignity in the workplace, and this is the type of thing we have to deal with in bargaining."

Fain has a Friday morning livestream scheduled with UAW members, during which he's expected to announce more strike targets in the absence of progress at the bargaining table. Ford factories were spared last week due to their willingness to move toward the UAW's demands on eliminating tiered wages, but the Dearborn, Michigan-based car company is now back in the hot seat.