Though many in the industry have been calling for independent CO2 and mpg tests, there are worries about the validity of the new initiative, which will only test vehicles unladen.

What Van? reckons the only vaguely valid approach would be to take the measurements with vans half laden. Any other routine will produce erroneous figures which bear no relationship to real world conditions.

“There is no reason why vans cannot be tested on a level playing field by running them unladen and fully loaded to produce the best and worst case scenarios,” said Mark Norman, values services manager at industry data expert Cap. “This would at least enable the end-user to make comparisons between vehicles on the basis of their independently assessed vehicle impact.”

As well as the criticism over the methodology, which several LCV manufacturers are also quietly concerned about, there are worries that an established CO2 figure, however accurate, could lead to a new method of taxing commercial vehicles.

“I wouldn't be at all surprised if Revenue & Customs or the DVLA look at a means by which they could base VED rates according to emission levels,” said Eddie Parker, CV manager at leasing firm Masterlease. “What concerns me slightly is that this could be the first step towards it being economically beneficial to drive on certain roads at certain times.”

Despite the worries, the figures will still impact on buying decisions. “I think, as with cars, there will be certain fleets where eco concerns are of paramount importance. If they are high profile in an area that's environmentally sensitive there will always be interest,” said Parker, who was also keen to point out that, as with cars, businesses shouldn't expect to see the claimed economy figures in the real world. “We'd hope astute operators understand that the engine probably wasn't fitted in the vehicle when it was tested and it was in a perfectly humidified and temperature-controlled environment.”