"The decline in the new car market is concerning but it's important to remember demand remains at historically high levels," said SMMT chief executive Mike Hawes.
"Falling business and consumer confidence is undoubtedly taking a toll, however, and confusing anti-diesel messages have caused many to hesitate before buying a new low emission diesel car." Hawes added: "Despite the overall decline, new car registrations remain high, with the market still the second biggest in the EU, behind Germany."