Britain’s biggest car manufacturers lobbied the government to delay a ban on petrol and diesel cars by warning that sales would plunge and jobs would be at risk from accelerating the transition to electric vehicles, the Guardian can reveal. The government announced in November that it would move forward a ban on the sale of pure internal combustion engine cars from 2040 to 2030, but said that it would allow the sale of hybrid vehicles until 2035, in a significant victory for the car industry. Carmakers including BMW, Ford, Honda, Jaguar Land Rover and McLaren argued strongly against a ban earlier than 2040, in written submissions to the government obtained by the Guardian. They also said plug-in hybrid cars should be exempted from the earlier deadline. Some of the claims made by the firms contradicted findings by environmental campaigners. The Society of Motor Manufacturers and Traders (SMMT), a lobby group, claimed in private modelling that a 2030 ban would cause UK car sales to drop from 2.3m in 2025 to only about 800,000 in that year. The 2035 ban would reduce UK car sales to about 1.2m in that year, it claimed, compared with more than 2m if a 2040 deadline was allowed. BMW, which also owns Mini and Rolls-Royce factories in the UK, said there was “no scientific evidence to support such ambitious market uptake in the UK” for the previous 2040 ban, let alone an earlier date. A BMW spokesman said the claim related to modelling of consumer demand for electric cars. The government decision to bring forward the deadline was partly based on advice from scientists on the Committee on Climate Change, which argued a total ban – including for hybrids – was needed by 2032 for the UK to meet its decarbonisation goals. Ministers admitted in December they had relented on plans to ban hybrids in 2030, partly because of the threat to British car factories, most of which produce hybrids. Honda and Ford both raised the spectre of job losses in manufacturing as part of their evidence. Lower sales would represent another heavy blow to the embattled industry. The warnings were made last summer, when the coronavirus pandemic had shut much of the UK car industry’s manufacturing and retail operations. That added to the challenge of trying to prepare for new post-Brexit trade rules and continued heavy investments in electric technology. The SMMT said any date earlier than 2040 “would put a significant strain on commercial viability”. The lobby group said its forecasts, made in June, did not reflect changes to the car market since the start of the pandemic. It called for the government to stop referring to the phase-out date as a ban, in the belief it would dent sales. It also argued vehicles like ambulances and hearses should be exempt, while McLaren argued supercars should be excluded. Greg Archer, UK director of Transport and Environment, a thinktank, said the industry was scaremongering about the transition from fossil fuels and that the forecasts for plummeting sales were “wholly pessimistic and unrealistic”. “The submissions made by carmakers illustrate their desperation to try to stop the government bringing forward the ban,” he said. “It illustrates a lack of honesty within large parts of the industry, painting a picture that the shift to electric cars will devastate UK carmaking when most companies are already making this transition. The debate about the type of cars we will drive in the future is now over: they will be battery electric.” Mike Hawes, the SMMT’s chief executive, said the new deadline left the industry with less than nine years to convince consumers to switch to electric vehicles. “Our concern is that until the cost and convenience of purchasing, running and charging an electric vehicle is as affordable and convenient as a conventional petrol or diesel one across all segments and for all types of drivers, some drivers will hold on to their trusted existing car,” he said. A government spokesperson said it was giving significant financial support to help the car industry’s transition to electric. “Bringing forward the phase-out date for all new cars and vans will put us on course to be the fastest in the G7 to do so, reducing greenhouse gas emissions equivalent to more than 4m fewer cars on the road each year out to 2050.” A Jaguar Land Rover spokeswoman said the company had accelerated its plans to electrify its products since the consultation response, including making its Jaguar brand electric only. A Honda spokesman said the company backed decarbonisation using technologies including battery electric, advanced hybrid, e-fuels and hydrogen. A McLaren spokesman said it supported the shift to zero-emission vehicles, but that hybrids should be included in the near term.