Vauxhall is aiming to take advantage of the stringent European Whole Vehicle Type Approval rules to step up its involvement in the light commercial vehicle conversion market. Steve Bryant, Vauxhall's commercial vehicle brand manager, said: "We are taking the lead on Type Approval. We have briefed body builders on the rules and we want to show converters we can work with them."

The legislation, which was phased in to cover major chassis cab conversions from April 2013, could put 25% of small vehicle body- building firms out of business, according to Ron Cocker, type approval manager at the Vehicle Builders and Repairers Association.

He said EWVTA would be a "bureaucratic nightmare" for specialist body builders that would place "a considerable burden on smaller companies".

He also claimed that the reduction in the number of converters would not reduce capacity in a sector where 20% of body builders make 80% of vehicles, but predicted that larger companies would move in to take up the slack and vehicle manufacturers would increasingly offer ready-to-run conversions.

Bryant said Vauxhall was working with recognised converters to exploit the market opportunity and cited the EWVTA rules as the catalyst for Vauxhall to ramp up conversion business as the number of market players declined.