The UK new car market declined for an eighth consecutive month in November, according to figures released by the Society of Motor Manufacturers and Traders (SMMT).
A total of 163,541 vehicles were registered, down 11.2% year-on-year, driven by a significant fall in diesel demand.
Petrol cars saw a gain of 5.0% on the same month last year to 92,944, and the Alternatively Fuelled Vehicles (AFV) sector was up 33.1% to 8,867.
However, these increases could not offset the 30.6% drop in diesel registrations to 61,730, following months of negative publicity.
In November 2016 diesel cars had a greater market share than petrol at 48.3% versus 48.1%, but a year later petrol cars were at 56.8%, compared with 37.7% for diesel.
Overall, registrations have declined 5.0% in the eleven months in 2017, with 2,388,144 cars hitting British roads so far this year.
SMMT chief executive Mike Hawes said: “An eighth month of decline in the new car market is a major concern, with falling business and consumer confidence exacerbated by ongoing anti-diesel messages from government. Diesel remains the right choice for many drivers, not least because of its fuel economy and lower CO2 emissions.
“The decision to tax the latest low emission diesels is a step backwards and will only discourage drivers from trading in their older, more polluting cars. Given fleet renewal is the fastest way to improve air quality, penalising the latest, cleanest diesels is counterproductive and will have detrimental environmental and economic consequences.”
RAC spokesman Rod Dennis commented: “From an air quality perspective, these latest figures are a mixed bag. There is encouraging growth in the alternatively-fuelled vehicles sector but this still represents a fraction of overall sales.
“The decline in new diesel sales however is stark. While the modest growth in petrol sales shows that some owners may be moving from diesel to petrol, it could also be evidence that diesel drivers are choosing to hold on to their current vehicles for longer when faced with uncertainty over future diesel taxes and charges.
“We believe drivers need to be offered more incentives to switch into alternatively-fuelled vehicles to encourage swifter uptake of the very cleanest vehicles available.”