California Attorney General Xavier Becerra promised to use “every legal tool at our disposal” if the Trump administration revokes the state’s authority to regulate automobile greenhouse gas emissions.

Bloomberg L.P. reported Monday that federal regulators this week will propose stripping California’s Clean Air Act waiver, which allows the Golden State to set its own stricter tailpipe emissions limits and to require the sale of zero-emission vehicles. Thirteen states and the District of Columbia follow California’s clean-car rules.