Among the incorrect statements is a claim that vehicles will have to be retested every year to establish their CO2 emissions levels, similar to an MoT, when the new tax is introduced in 2002.
Another claim suggested that individual tax offices might amend the way the tax is implemented as they see fit, so different testing procedures could be introduced around the country, creating chaos for company car fleets.
Mary Braim, policy adviser on transport benefits at the Inland Revenue, said: 'The information fleet managers have been given is completely wrong. As we have already said, vehicles produced between 1998 and 2001 will use CO2 emissions figures provided by the Society of Motor Manufacturers and Traders or the Vehicle Certification Agency. From 2001, the figures will be with the car's registration details.
'We will be getting very clear guidance out to all our officials as soon as possible, but they already have access to our website and general information, but what some have been telling fleet managers is wrong.'
The crisis has raised concerns among fleet managers who already have to advise drivers taking on new cars that will fall under the new tax in two years' time.