The battle of words over a proposed bonus tax credit for EVs built by U.S. unions festered as Toyota sent a memo to its workers about comments made by Sen. Debbie Stabenow.

A proposed U.S. electric vehicle tax credit that favors union-built vehicles is "discriminatory" and Mexico is analyzing a range of legal actions in response, including tariffs.

The ad is asking Congress to "put politics aside" and apply the EV tax credit equally to all electric vehicles assembled by U.S. auto workers.

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.