One in four cars sold in the UK last month was electric, according to industry figures, but new registrations were driven by steep discounting.
Electric car sales grew in November for the 11th consecutive month, according to the Society of Motor Manufacturers and Traders (SMMT) as carmakers raced to meet tough targets.
Manufacturers gave “massive” discounts worth around £4bn on electric vehicles (EVs), the SMMT said.
Some firms are expected to miss the government’s electric vehicle (EV) sales targets this year and could face fines, but flexibilities in the rules mean this is unlikely.
The rules say carmakers have to sell a certain amount of EVs but they are able to buy sales credits from other firms or “borrow” from their own quotas in future years.
SMMT chief executive Mike Hawes said manufacturers were investing in electric vehicles “at unprecedented levels” and “spending billions on compelling offers”.
But he added: “Such incentives are unsustainable – industry cannot deliver the UK’s world-leading ambitions alone.”
New electric car registrations bucked a general downwards trend for other vehicles.
Although the bulk of demand for new cars came from fleet sales to businesses, this sector still saw sales fall overall. Private buyer sales also dropped.
Sales of new petrol cars fell by more than 17%, diesel cars fell by more than 10%, while hybrids and plug-in hybrids dropped by more than 3% and 1% respectively.
Read more: BBC