General Motors, Toyota, and Fiat Chrysler Automobiles, among other carmakers, announced Monday that they were supporting US President Donald Trump’s bid to block California from setting its own strict emission standards. The automakers have backed the Trump administration’s proposal to prohibit individual emission standards by state, saying “The certainty of one national program, with reasonable, achievable standards, is the surest way to reduce emissions in the timeliest manner.” This is in response to California’s complaint against the Trump administration that was filed in September when California sought to block the administration’s challenge of its strong emission standards.

California has been supported by several other automakers and environmental groups in its suit against the Trump administration. This litigation represents a divide within the auto industry regarding the issue of whether individual states should set car emission standards or whether the federal government should set a single standard.