Demand for new cars fell by around a quarter last month compared with October 2020.
The Society of Motor Manufacturers and Traders (SMMT), which released the preliminary data, said it expects a total of 1.66 million new cars to be registered in the UK this year.
That would represent a 1.9% increase on 2020.
Uptake of plug-in vehicles began to accelerate during 2020 and accounts for more than 16% of all new cars registered in the UK this year.
The SMMT forecasts that some 287,000 of those vehicles will be registered across the whole of 2021, which would be more than every year combined from 2010 to 2019.
The organisation’s chief executive Mike Hawes said: “Massive investment by industry as well as long-standing Government incentives have seen us go from just 188 new plug-in cars in 2010 to almost 300,000 in 2021.
“To achieve net zero by the desired date, however, uptake rates must continue to grow.
“This requires ongoing incentives to help consumers make the switch and significant investment in public charging infrastructure. Backed by the ingenuity and innovation of the automotive sector, we can then deliver zero-emission mobility that is accessible and affordable for all.”
The UK has pledged to reduce greenhouse gas emissions to net zero by 2050.
Jim Holder, editorial director of magazine and website What Car?, said: “Against the backdrop of Cop26, perhaps the most positive message from the October new car registrations is the strong battery electric vehicle performance.
“This has been the fastest-growing new car segment in the UK for some time now, and will only continue to grow as manufacturers continue to expand their electric line-ups and offer customers a wider array of exciting new vehicles.”
Mr Holder added that the industry is continuing to struggle with the global shortage of microchips, which is leading to some manufacturers having waiting times of more than 12 months for new cars to be available.