Under changes announced by Chancellor of the Exchequer Gordon Brown, 85% of van drivers with limited private use will be taken out of the vehicle tax system altogether.
This is a major boost for van fleets which feared a complicated emissions-based tax was set to be introduced, after the idea was raised in a consultation document last year.
But for those that remain, there will be massive increases, from the current tax liability of £500 to £3,000 from 2007, with an extra £500 tax liability if the driver receives free fuel for private mileage.
The changes are designed to wipe out a loophole that allows company car drivers to switch from a car into a double-cab pick-up and save thousands of pounds in tax.
The three-year delay gives drivers time to switch out of their current vehicles in the natural fleet replacement cycle, as long as they are warned of the change by their fleet managers.
Interleasing business development finance manager Gavin Keer-Keer warned the blanket approach could affect many other fleets: 'This will have a significant impact on company logistics. While weekend 'white van man' may become a thing of the past, businesses will have to look at how they store vans abandoned by the regular users.'
Importantly, if the only private use drivers have is home to work travel, then they will be exempt from benefit-in-kind tax.
But if there is any further private use the tax charge will rocket.
LeasePlan commercial director Ian Goswell added: 'This is steep by any standard and it will be interesting to monitor what effect these new rules will have on the sales of double-cabs.
'As most of them are priced at the £20,000 mark, it is a fair assumption that a lot of the people buying them will be subject to the higher tax level and I'd imagine they would regard this as a hefty penalty.'
ALD Automotive managing director Keith Allen said: 'I believe this massive increase is aimed squarely at stopping employees opting out of traditional company cars and into double-cabs for tax reasons. The Chancellor's announcement will kill the double-cab market as quickly as it took off.'
A spokesman for the Society of Motor Manufacturers and Traders added: 'Given that there's been so much publicity recently about how the double-cabs exploit the rules, I suppose the motivation was there for this loophole to be closed.'
But there was widespread support for the decision to take most van drivers who have marginal private use out of the benefit-in-kind tax system.
The SMMT spokesman added: 'This is good news and we are relieved that this approach has been taken for drivers who travel to and from their work in company vans.
'The Chancellor of the Exchequer has dealt with this issue in a sensible way.'