New car sales have fallen for the first time in six years, with overall sales dropping by 5.7% in 2017 and diesel sales plummeting by almost a fifth.
Industry insiders are also predicting a 5% to 7% fall in total sales this year.
About 2.5 million cars were registered in 2017 in total, according to provisional figures from industry body the Society of Motor Manufacturers and Traders (SMMT).
The figure was down 5.7% from 2016, while diesel sales fell 17.1% after consumer demand has been rocked over recent months and years by higher taxes and fears around pollution.
However, while diesel cars produce more toxic nitrogen oxide they also produce lower CO2 emissions.
SMMT chief executive Mike Hawes said the drop in diesel sales was ‘the prime cause’ of a 0.8% rise in CO2 emissions from new cars last year – the first such increase in 20 years.
Mr Hawes said the latest low-emission diesels were ‘vital’ in meeting climate change targets. SMMT representatives also pointed to the major improvements in making diesel engines less polluting in recent years, more accurate on-road testing in the wake of the VW scandal, their lower cost and fuel efficiency.
Diesel car sales fell by almost a third in December after November’s Budget introduced a new levy – which comes into effect in April – on diesels that fail to meet the latest emissions standards.
Sales of alternatively-fuelled vehicles (AFVs) – including electric cars – rose by 41%, up from 16,000 vehicles to over 22,000. Sales of new petrol and diesel engine cars are to be banned in the UK from 2040.