A LEGAL battle to defend Britain's imperial measurements against the metrification of Brussels opened yesterday before magistrates who will be asked to decide on a matter of constitutional importance.

At the centre of the landmark case is fruit and veg market trader Steven Thorburn, 36, who is being prosecuted for refusing to convert from traditional pounds and ounces to Euro-approved metric measures.

Thorburn, the first British trader to be prosecuted under regulations that came into effect on January 1, denied two charges under Section II (2) of the 1985 Weights and Measures Act.

Police and local authority trading standards officers raided Mr Thorburn's market stall in the Southwick area of Sunderland in July and confiscated his imperial scales.

Sunderland City Council said the father-of-two had failed to comply with a notice issued by its officers to convert to metric measures.

His case was immediately picked up by the UK Independence Party which claims traders have the legal right to use imperial scales under the 1985 Weight and Measures Act.

Constitutional barrister Michael Shrimpton, defending, told Sunderland magistrates there was no dispute between the prosecution and defence over the facts of the matter, but over the law.

He argues the 1994 Units of Measurement Regulations, intended to make Britain comply with EU directives on metrification, cannot overrule a primary legislation of an Act of Parliament.

Mr Thorburn, 36, who could face a £5,000 fine and get a criminal record if found guilty, will face a three-day trial on January 15.