A total of 2,838 ULEVs were registered between January and May 2014, calculated based on their eligibility for the Plug-in Car Grant, which offers £5,000 or up to 25% off the purchase price.

Within that, plug-in hybrid and range-extenders recorded the largest increase, accounting for the majority of the total. In the first five months of 2015, 8,147 were registered in the UK – a 766% increase on 2014, led by the popularity of the Mitsubishi Outlander PHEV.

Plug-in hybrids and range extenders accounted for 69% of the total ULEV registrations for the year to date, compared with 33% during 2014. This is despite pure electric vehicle registrations doubling, from 1,897 units to 3,772, during the same period.

Hybrids, including petrol and diesel models with no option to plug in, totalled 18,903 registrations to the end of May, a 16% increase on last year’s 16,339 units. Of the 30,745 alternative fuel vehicles registered during the first five months of 2015, 39% were ULEVs – up from 14% of the 19,177 registered last year.

Mike Hawes, SMMT Chief Executive, said: "The remarkable growth in demand for plug-in vehicles is expected to continue as the range of ultra-low emission vehicles on sale increases. Meanwhile, we anticipate a natural levelling out of the overall new car market throughout the remainder of 2015.”