The company's report says that values rose by 14.7% during the first three months of 2010. This compares to an increase of 11.3% in average values in the equivalent first three months of 2009.

Used van values were particularly boosted last month, up by 5.6% (£224). This follows a rise of 4.4% (£169) in February and is the ninth month in a row that values have improved.

Average values have now increased in all but two of the last 14 months. Compared with March 2009 average wholesale used van prices are actually up by a staggering 47.5% (£1,365) with the same average age of 54 months and average mileage 3,544 miles higher at 74,202.

Notable examples of the increases in average month-on-month values in March include Large Panel Vans less than 3.0t, up by 4.4% (£168 to £3,943); Large Panel Vans greater than 3.0t, up by 2.5% (£104 to £4,234) and 4x4s, up by 9.3% (£633 to £7,454). At 54 months, average age in March was static when compared with February while average mileage was higher by 306 miles at 74,202.

James Davis, general manager, commercial vehicles, Manheim Auctions, said: 'There seems to be no end to the continued increase in wholesale values at the moment and certainly no evidence yet of the traditional seasonal softening of the market. Demand remains very strong while the relative lack of supply continues to affect values. The imminent general election may create some market uncertainty during April but the overall upward trend in values looks likely to continue in the medium term.'