LONDON (Reuters) - A British traffic officer caught driving at 159 mph but cleared by a court of speeding and dangerous driving faces a legal move at the High Court in London Wednesday to convict him.

The Attorney General will appeal against the acquittal of constable Mark Milton and seek a High Court order that the advanced police driver should be convicted over his high speed blast in the early hours of December 5, 2003.

Milton, a qualified advanced driver, was recorded by an onboard camera in his upgraded unmarked Vauxhall Vectra police car traveling at 91 mph in a 30 mph zone and hitting 159 mph on the M54 motorway. The legal limit in Britain is 70 mph.

Milton's defense, accepted by the local judge in May 2005, was that he had taken the car on a test run around Telford, Shropshire, where he was based.

The judge said the prosecution had failed to prove beyond reasonable doubt that he had driven dangerously and that the car was being "used for police purposes" when the incident occurred.

The ruling prompted outrage in the media and condemnation from motoring groups.

Wednesday, lawyers for the Attorney General will argue the district judge erred in law when he made his judgment.