And once it does become the national standard, motorists could be forced to wait weeks to have their cars tested at e-enabled stations.

Following AM's December 6 front page story in which the Vehicle Inspectorate admitted national roll-out of the scheme had been delayed by a year until at least January, 2004, Snap-on Sun Tech's UK sales director Richard Tomkins is predicting months of confusion while the traditional test procedure and the new system run side by side.

The VI proposes to trial e-MoTs with up to 1000 volunteer VTSs by the end of this year and then introduce them gradually as the industry standard from 2004.

"We could face the ridiculous situation where one station in a town operates the VI's computerised system and updated equipment while another is still using the current method and issuing hand-written certificates," says Tomkins.

"This will inevitably lead to double standards, where a car might fail an emissions test at a computerised station but pass it at one down the road which hasn't become computerised - and which may also still be charging the motorist less for it."

Ian Parrott, who operates two VTSs in Norfolk and runs the motuk.co.uk database and advice service, welcomes eventual computerisation as the catalyst that will provide a true national test standard and put back a measure of profitability into the MoT business.

"By the time the scheme is fully live, there will be an immediate shortage of stations qualified to issue MoTs," says Parrott.

"In some areas that will create long waiting lists, but it will also put an end to the practice of discounting MoT fees."