Donald Trump’s Environmental Protection Agency is expected to roll back greenhouse gas emissions and fuel economy standards for automobiles, further undercutting his predecessor Barack Obama’s aims to battle climate change. 

The move could set up a huge legal fight with California, which has promised to stick with the stricter rules even if the federal government weakens standards.  

A draft of the plan is currently being reviewed by the White House, EPA spokesperson Liz Bowman told The Independent in a statement. 

“The draft determination has been sent to OMB [Office of Management and Budget] and is undergoing interagency review,” she said. “A final determination will be signed by April 1, 2018”.

EPA chief Scott Pruitt will likely frame the plan to the public as the elimination of a regulatory burden on automakers that will result in more affordable trucks, vans and sport utility vehicles for buyers, people familiar with the initiative told the New York Times.

Several major car manufacturers are expected to welcome the change, while environmental experts warn that it could lead to greater total gasoline consumption and a large increase in emissions of greenhouse gases. 

Aseem Prakash, the founding director of the University of Washington’s Centre for Environmental Politics, said Mr Trump’s argument that Barack Obama’s climate policies were making US automakers uncompetitive is a “bit untrue”. Many consumers are willing to spend more on fuel-efficient vehicles if they calculate that they will spend less money on gas later, Mr Prakash told The Independent

He said the plan to weaken fuel economy standards for cars was just part of a “systematic assault on Obama’s climate policy”.

“It’s a carefully orchestrated political plan that appeals to the president’s core supporters,” Mr Prakash said.

Mr Trump last year signed an executive order to roll back policies from the Obama administration aimed at curbing greenhouse gas emissions. He has also withdrawn the US from the Paris climate accord – a global agreement to cut carbon emissions to slow the worst effects of climate change. Mr Trump said partaking in the deal would impose “draconian financial and economic burdens” on the US.

Right now, California is exempt from having to roll back the climate regulations on automobiles. The state has a special waiver under the 1970 Clean Air Act that empowers it to enforce stronger air pollution standards than those set by the federal government. 

If the EPA revokes California’s waiver, the Trump administration could almost assuredly expect a nasty courtroom battle. 

“We’re prepared to do everything we need to defend the process,” Xavier Becerra, the attorney general of California, told the Times

Nives Dolšak, a professor at the University of Washington’s School of Marine and Environmental Affairs, said the Clean Air Act identifies three conditions in which the EPA could deny California its waiver.

“None of those conditions seem to apply in this case,” she told The Independent. “It will be a prolonged legal battle if they do not grant the waiver for California.”

Other states that have established stricter air pollution standards than the federal government would also likely join in on the action, she said.

Even if the Trump administration doesn’t revoke the waiver, the different standards across the US would create problems for auto companies by dividing the country into at least two distinct markets.