Purchases of popular models like the Tesla Model 3 and the Ford Mustang Mach-E may no longer entitle buyers to tax savings because the cars do not meet tougher sourcing requirements.
The United Automobile Workers’ effort, with a long-elusive goal, follows its success in securing big raises in contracts with the Detroit automakers.
The three U.S. automakers say they are already at a disadvantage to nonunion rivals while labor leaders hope that big gains in negotiations will inspire workers in Southern states to unionize.