The proposal would boost consumer tax credits to as much as $12,500 for EVs assembled in a factory represented by unions with U.S.- produced batteries.

The law signed Tuesday immediately ends credits for about 70 percent of the 72 models that were previously eligible, said the Alliance for Automotive Innovation.

What appeared to be a path forward on EV tax credits at first glance evolved into a last-minute scramble, as automakers and some Senate Democrats seek changes to the provision's strict battery content and assembly rules, which they said could delay vehicle eligibility.