Trump to block California from setting vehicle emissions rules

Administration will declare that states are pre-empted from setting their own standards in a move that will spark challenge

The Trump administration is poised to end California's authority to set its own vehicle emissions standards and bar states from establishing their own regulations.

Conservative and free-market groups have been invited to attend an announcement of the rollback Wednesday afternoon at the Environmental Protection Agency (EPA) headquarters in Washington. The widely reported announcement is sure to spark a furious legal challenge.