Leading U.S. automakers are making an 11th-hour push to stop the Trump administration from dramatically weakening Obama-era fuel efficiency standards, warning doing so would bring “untenable” uncertainty and lead to drawn-out litigation.

In a letter to President Trump, 17 companies including Ford, General Motors, Toyota, and Volvo, asked him to return to the negotiating table with California, which, with more than a dozen other states, is poised to sue the administration in order to enforce stricter auto pollution rules to limit carbon emissions from transportation, the highest-emitting economic sector. The companies also sent a letter to California Gov. Gavin Newsom, a Democrat, requesting the same thing.