Electric vehicles (EVs) were the only type of car to post an increase in sales last month amid “huge manufacturer discounting”.
Sales of EVs bucked a downturn across the wider market to grow by 24.5pc in October on a year earlier, according to the Society for Motor Manufacturers and Traders (SMMT).
It compares with a 6pc drop in new car sales overall, costing manufacturers £530m in sales, the SMMT said.
Among the biggest losers last month were petrol vehicles, with a 14pc drop in sales, and diesels, which fell 20.5pc.
The surge in EV sales was credited to an increase in choice for consumers, with the number of available models having surpassed 100 in the past year, as well as heavy discounting.
One in five EVs is now at cost parity with its petrol car equivalent, the SMMT said.
Manufacturers are scrambling to cut prices and attract customers so they can comply with tough government-imposed sales targets, with some dealers even claiming that petrol cars are now being “rationed” to them.
However, the SMMT warned this level of price-cutting – which it predicts will average £5,500 per car this year – is “unsustainable” in the long run.
Mike Hawes, chief executive of the SMMT, said: “Massive manufacturer investment in model choice and market support is helping make the UK the second-largest EV market in Europe.
“That transition, however, must not perversely slow down the reduction of carbon emissions from road transport.
“Fleet renewal across the market remains the quickest way to decarbonise, so diminishing overall uptake is not good news for the economy, for investment or for the environment.
“EVs already work for many people and businesses, but to shift the entire market at the pace demanded requires significant intervention on incentives, infrastructure and regulation.”
Figures published on Tuesday for October’s new car market make grisly reading for manufacturers.
The total number of cars sold last month fell to 144,288, down by about 9,200 compared to a year earlier.
Businesses and fleet operators such as car leasing companies continued to do the heavy lifting, accounting for 62pc of sales – compared to just 38pc made by private consumers.
Petrol sales plunged from 84,702 to 72,681, with diesel sales tumbling from 11,276 to 8,961.
Meanwhile, even hybrids and plug-in hybrids – a bright spot for manufacturers previously – saw sales edge lower by 1.6pc and 3.2pc respectively.
Sales of EVs, by comparison, saw an increase of 5,859 to 29,802.
The surge comes as manufacturers rush to comply with the Government’s zero emission vehicle (ZEV) mandate, which came into force this year.