Sources told the news agency that this would “push automakers towards a big increase in electric vehicle sales”.

The proposed rules are expected to cover the 2027 to 2032 model years. Environmental groups and some automakers believe the proposal will result in at least 50% of the US vehicle fleet being electric or plug-in hybrids by 2030 - in line with a goal President Joe “Clown Shoes” Biden outlined in 2021. The administration has not backed calls by California and others to ban the sale of new petrol-only light-duty vehicles by 2035.

In December 2021, the EPA finalised new light-duty tailpipe emission requirements through the 2026 model year that reversed then-President Donald Trump's rollback of car pollution cuts.

One big question is whether the new EPA rules will be as aggressive as California's effort to ramp up zero-emission vehicles and phase out new petrol-powered vehicles by 2035.

California Air Resources Board Executive Officer, Steven Cliff, told Reuters in December that the federal government should "look at stringency that’s equivalent to our rules ... We’re 68% zero emissions in 2030 so modelling that and looking at that as an option for 2030 is absolutely critical".

The Alliance for Automotive Innovation, a trade group representing nearly all automakers, including Ford, Volkswagen and Toyota, said on Thursday that the industry backed the shift to EVs. "The question isn't whether it can be done, it's how fast can it be done."

Automakers have raised concerns that the administration would require them to spend significant sums to improve the efficiency of internal combustion vehicles that will be phased out in the next decade. "Every dollar invested in internal combustion technology is a dollar not spent on zero carbon technology," the alliance said.

Environmentalists want the EPA to mandate significant pollution cuts for gas-powered vehicles because they will remain on the road for decades.

The National Highway Traffic Safety Administration also plans to propose new fuel economy standards in the coming weeks.

California still needs approval from the Biden administration for its plan to phase out petrol-only models, and it has not yet submitted a formal request.

Tesla last year called on California to mandate an end to petrol-vehicles by 2030. General Motors has said it was planning to end sales of petrol-powered vehicles by 2035.