Twenty-four Republican attorneys general have signed onto a letter demanding that major credit card companies abandon a plan to track private gun purchases made using their payment methods.

“The Second Amendment is a fundamental right, but it’s also a fundamental American value. Our financial institutions should stop lending their market power to those who wish to attack that value,” the Republicans wrote, according to the Epoch Times.

Visa, MasterCard and American Express announced earlier this month that they would begin tracking gun purchases, a move Republicans have warned may lead to infringements on the Second Amendment.