Lynn Robson, 60, was slapped with a £60 fixed penalty notice after he was snapped doing 34mph in a 30mph zone from a speed camera set up inside a van by the side of the road.
But he refused to accept the fine and three penalty points and is fighting the notice because he believes the camera used to catch him is being operated "illegally".
He says he has evidence from the Home Office, which states the Gatso 24 radar speed camera that caught him should not have been filming from inside a van. But Safe Speed for Life, which operate the cameras, said it is confident the devices are legal.
Magistrates will now debate the decision, which could have massive implications for anyone issued with a speeding fine from a mobile camera mounted inside a Safe Speed van.
Mr Robson's Citroen C5 estate was snapped on North Road in Hetton, Sunderland, on February 20, but he is adamant he was driving under the 30mph limit.
After receiving the notice, he began to research the guidelines for the use of the cameras and was stunned by his discovery.
Guidelines issued by the Association of Chief Police Officers (Acpo) state the type of camera used on our roads by Safe Speed For Life should not be mounted inside a vehicle.
He said: "The guidelines are clear. If they are not followed then surely this is a direct breach of operational use. They are just not legal."
Mark McArthur-Christie, from the Association of British Drivers, said if Mr Robson is successful, it could open the floodgates for thousands of drivers.
He said: "Drivers are having to look up the law to defend themselves because they feel so hard done by."
A Home Office spokeswoman said: "The Gatso radar type 24 can be used from the rear of a stationary vehicle, provided the Acpo Code of Practice and the manufacturer's instructions are followed and no digital radios are transmitting on or inside the vehicle."
By LISA HODGE
gazette.news@northeast-press.co.uk