New car registrations last month fell 9.3% – marking the first time the important September market has fallen in six years.

Diesel registrations fell 21.7% in September.

Described as a cause of “considerable concern” by the Society of Motor Manufacturers and Traders (SMMT), the fall is the sixth consecutive month of decline and is said to be the result of confusion over air quality plans as well as economic and political uncertainty.

Within the fleet market, registrations last month fell 10.1% to 200,289 units while sub-25 ‘business’ registrations were down 5.2% to 21,826. The retail market also declined, with an 8.8% fall to 204,055.

The month also saw diesel registrations continue to slide with a 21.7% fall, while petrol was down 1.2%. Registrations of alternatively fuelled vehicles (AFVs) were up 41.0% to 22,628 units.

Year-to-date, the overall market fell 3.9% to 2,066,411 units. The fleet market was down 2.1% to 1,059,999 units with business registrations seeing a 1.7% fall to 83,429 units and private registrations declining 6.1% to 922,983. Diesel registrations were down 13.7%, with petrol up 3.0% and AFVs up 34.6%.

Mike Hawes, SMMT chief executive, said: “September is always a barometer of the health of the UK new car market so this decline will cause considerable concern. Business and political uncertainty is reducing buyer confidence, with consumers and businesses more likely to delay big ticket purchases.”

He added: “The confusion surrounding air quality plans has not helped, but consumers should be reassured that all the new diesel and petrol models on the market will not face any bans or additional charges. Manufacturers’ scrappage schemes are proving popular and such schemes are to be encouraged given fleet renewal is the best way to address environmental issues in our towns and cities.”

However, his comments on scrappage schemes come as latest Kwik Fit research suggests that it will need major price reductions to get motorists on to dealers’ forecourts.

The study indicates that only one in six (16%) of those considering a new car in the next two years are planning on buying a diesel, compared to 42% opting for petrol, 19% choosing a hybrid, 8% preparing to go fully electric and the remainder undecided.

Although some car buyers could be tempted to opt for the latest diesel models, they would need hefty discounts to do so. The average motorist would want a new diesel car to be 18.4% cheaper than the petrol equivalent for them to consider buying it. And those who currently drive a diesel would still want an average 13.5% off the windscreen sticker price, compared to the 21.7% discount wanted by the average petrol car driver.For more of the latest industry news, click here.