Fruit and vegetable traders who sell their produce using imperial measures will not be prosecuted, under guidelines being drawn up by the Government.

The Department for Innovation, Universities and Skills said that it was updating advice to councils to ensure that action against so-called metric martyrs was “proportionate, consistent and in the public and consumers’ interest”.

John Denham, the Innovation Secretary, is expected to issue his proposals within months. They will mean that traders who insist on selling goods in pounds and ounces, despite European Union laws, will not be taken to court by local authorities.

It is understood that the decision was prompted by the case of Janet Devers, 64, the East London market trader who was made to pay nearly £5,000 in costs and received a criminal record this month after a prosecution brought by Hackney council. She was found guilty of using imperial weighing scales without an official stamp and of selling vegetables for £1 a bowl rather than counting them out individually.

Mr Denham, who has responsibility for weights and measures as part of his science brief, said: “It is hard to see how it is in the public interest, or in the interests of consumers, to prosecute small traders who have committed what are essentially minor offences. I would like to see an end to this kind of prosecution, which is why I have asked for new guidance to be introduced.”

Neil Herron, director of the Metric Martyrs campaign group, said that the decision was a “spectacular victory for people power” and dedicated the victory to Steven Thoburn, a greengrocer from Sunderland who died in 2004 at the age of 39 while fighting a conviction for selling bananas by the pound.

Mr Herron said: “Finally we have a government minister with an ounce of common sense.”

In 2001 Mr Thoburn became the first man to face prosecution for using scales that could not weigh in metric units. He was given a six-month conditional discharge but his case, along with three others, went to the Court of Appeal, where the convictions were upheld. He took his appeal to the European Court of Human Rights, where it was rejected. He died of a heart attack three years later. Mr Thoburn’s widow, Leigh, said: “This is absolutely fabulous news, but it is a tragedy that it had to come to this in the first place.”

John Gardner, director of the British Weights and Measures Association, said that he “warmly welcomed” the guidance. He said: “The proper role of Trading Standards is to check whether customers are receiving what they pay for, not persecuting shopkeepers and stallholders whose only crime is selling apples in pounds and ounces, not grams and kilos.”

Metric measurements were introduced in Britain in the 1970s. Under legislation that came into force on January 2000, all goods sold loose by weight are required to be sold in grams and kilograms. Traders can still display weights in imperial but a conversion must also be given.

A spokesman for the Department for Innovation, Universities and Skills said: “While individual enforcement decisions are rightly a matter for Trading Standards, we are keen to encourage action that is proportionate, consistent and in the public and consumers’ interest, which is why the National Weights and Measures Laboratory is updating guidance with local authority bodies for Trading Standards officers. We are reviewing the current legislative framework with a view to making it easier for everyone to understand, business to comply with and Trading Standards officers to enforce.”

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