The average figure was 119g/km, while some 20% of all new cars ordered across the 18,400-strong Fleet Alliance vehicle fleet were sub-100g/km of CO2, compared with 16% in 2014.

At the same time, 77% of the fleet had CO2 figures of less than 130g/km, compared to 71% at the end of 2014.

In a league table of the cleanest cars, the top 10 models on the company fleet all had carbon emissions of 100g/km or less:

During the last 12-18 months, Fleet Alliance has been continually advising fleet clients of the importance of setting fleet policies that encourage the take-up of low carbon-emitting cars to capitalise on savings in tax, National Insurance and fuel costs.

To reinforce the message, the company has also introduced a number of new green initiatives including an EV awareness programme, which included adding two new examples of the Nissan Leaf to the Fleet Alliance fleet for testing and review purposes.

Fleet Alliance also published its top 10 list of volume best sellers:

Fleet Alliance managing director, Martin Brown commented: “In terms of the volume sellers, Audi still remains desirable for user-choosers with their low carbon emissions and smaller tax charges. So it was of little surprise that the number one car on our fleet in 2015 was the Audi A3.

“In fact, despite the much-publicised emissions issue, Volkswagen Group had three models in our top ten with the Passat and Golf in second and fifth places respectively, as well as the A3 at number one.

“There was another strong performance from Kia, who are now producing low carbon-emitting, models ideal for today’s fleet market, while the best-selling Nissan Qashqai also featured at number six, reflecting the strong current demand for SUVs.

“The success of models like the Vauxhall Insignia, the Land Rover Evoque and the Audi A6, on the other hand, reflects the number of new customers we have taken on in the mid-size corporate market in the last 12 months,” he added.