The Labour government in April worried some electric carmakers by weakening rules, known as the zero-emission vehicle (ZEV) mandate. The mandate forces increased sales of EVs each year, but new loopholes allowed carmakers to sell more petrol and diesel cars.

New taxes on electric cars in last week’s budget could further undermine demand, critics have said.

Carmakers including BMW, Jaguar Land Rover, Nissan and Toyota – all of which have UK factories – claimed in their submissions to the consultation in spring that the mandate was damaging investment, because they were selling electric cars at a loss. However, environmental campaigners and brands that mainly manufacture electric vehicles said the rules were having the intended effect, and no carmakers are thought to have faced fines for sales in 2024.

Tesla argued it was “essential” for electric car sales that the government did not introduce new loopholes, known as “flexibilities”.

Changes “will suppress battery electric vehicle (BEV) supply, carry a significant emissions impact and risk the UK missing its carbon budgets”, Tesla said.

The chancellor, Rachel Reeves, alarmed carmakers further at the budget with the promised imposition of a “pay-per-mile” charge on electric cars from 2028, which is likely to reduce their attractiveness relative to much more polluting petrol and diesel models. At the same time, she announced the extension of grants for new electric cars, which the sector has welcomed.

Tom Riley, the author of the Fast Charge, said: “Just as the EV transition looked settled, the budget pulled it in two directions at once – effectively robbing Peter to pay Paul. If carmakers push again for a softer mandate, Labour only has itself to blame when climate targets slip.”

Tesla, Mercedes-Benz and Ford objected to their responses being shared, and were only obtained on appeal under freedom of information law. Several pages were heavily redacted, with one heading left showing Tesla called for “support for the used-car market”. Tesla declined to comment on whether that support would include grants.

In contrast, the US carmaker Ford and Germany’s Mercedes-Benz lobbied against more stringent rules after 2030 that would have forced them to cut average carbon dioxide emissions further – potentially allowing them to sell more-polluting vehicles for longer.

Ford strongly criticised European governments for pulling support for electric car sales, saying that “policymakers in many European jurisdictions have not delivered their side of the deal”. Ford has U-turned after previously backing stronger targets.

The US carmaker also pointed to the threat of being undercut by Chinese manufacturers that “do not have a UK footprint and benefit from a lower cost base”.

Mercedes-Benz argued that the UK should cut VAT on public charging from 20% to 5% to match home electricity, and added that it should consider a price cap on public charging rates.

Tesla also called for a ban on sales of plug-in hybrid electric vehicles with a battery-only range of less than 100 miles after 2030 – a limit that would have ruled out many of the bestselling models in that category.

Ford, Mercedes-Benz and Tesla declined to comment further.