The number of new cars sold in Britain last year fell to its lowest since 2013, as consumers held back from purchases amid increased restrictions on diesel vehicles and ongoing economic uncertainty in the run-up to Brexit.

New car registrations dropped by 2% in 2019 to 2.31 million, according to provisional data from the Society of Motor Manufacturers and Traders (SMMT), the third annual fall since sales peaked at 2.69 million in 2016.

"Undoubtedly consumer confidence on big-ticket items is still very weak," SMMT Chief Executive Mike Hawes said.

Sales in December alone were up 4% from a year earlier, when stocks of some models were limited pending new emissions tests.

Brexit remained the industry's top concern, Hawes said, due to the risk of 10% tariffs on imports and exports of cars in 2021 if Prime Minister Boris Johnson cannot negotiate a post-Brexit trade deal with the European Union before then.

A tariff of this level would make a lot of car production in Britain uneconomic, and the risk of this has caused many manufacturers' investment plans to stall, he added.