One of the nation’s most powerful labor unions is threatening to drop its participation in Wells Fargo’s mortgage program unless the San Francisco-based lender severs its ties with the National Rifle Association (NRA).

The American Federation of Teachers (AFT) claimed that Wells Fargo “continues to bankroll the NRA and help gun manufacturers such as American Outdoor Brands Corp. (the parent company of Smith & Wesson) and Vista Outdoor borrow hundreds of millions of dollars.” The AFT said it would drop the Wells Fargo mortgage program from its Union Privilege program and urge other labor unions to do the same.

“We’re issuing Wells Fargo an ultimatum,” said AFT President Randi Weingarten. “They can have a mortgage market that includes America’s teachers, or they can continue to do business with the NRA and gun manufacturers. They can’t do both.”

In a response to Weingarten’s threat , Wells Fargo President and CEO Timothy J. Sloan noted his company assisted 1,600 AFT families with home financing and offers grants and interest-free loans to AFT members in the event of a strike, layoff, or a disability. However, he also questioned Weingarten’s attempt to muscle Wells Fargo on matters unrelated to home loans.

“When dealing with the safety of our families, children, and other issues of this magnitude, there are no easy or satisfying solutions,” Sloan stated. “In fact, as I have publicly stated, I do not believe that the American public wants banks to decide which legal products consumers can and cannot buy. What we can pledge is that Wells Fargo will be a thoughtful participant in the dialogue and listen carefully to all voices and all points of view, taking each of them seriously, including those of the AFT.”