Steve Thoburn made headlines around the world over his campaign

In 2001, grocer Steve Thoburn became famous after being convicted for using scales showing only imperial weights.

The UK had been preparing to phase out imperial measurements, but on Tuesday the EU is expected to allow traders to continue using pounds, miles and pints.

Campaigners say pardoning Mr Thoburn, who died in 2004, would end the matter.

The Metric Martyrs group says he deserves a posthumous pardon - though consumer watchdogs said the new EU decision would not have affected the circumstances of his offence.

The greengrocer hit the headlines after his scales were seized from his market stall by trading standards officers .

It's a tragedy that he's not here to celebrate, but now the campaign has to be brought to its natural conclusion - a full pardon Neil Heron

He was convicted of breaching the Weights and Measures Act 1985 and given a six-month conditional discharge.

The Metric Martyr group's appeals against conviction were rejected all the way up to the House of Lords and, in February 2004, by the European Court of Human Rights.

Mr Thoburn died of a heart attack the following month.

The UK had been due to set a date for phasing out all its imperial measurements within three years, but the European Commission will announce later it is leaving all future decisions to the British government.

The Metric Martyrs have hailed the move as a victory for their campaign to clear Mr Thoburn's name, despite the fact it will still be illegal to use imperial-only scales.

Neil Heron, the campaign director who has organised a petition calling for a royal pardon, said: "It is true that if Steve did today what he did in 2001, he could still be prosecuted, but that doesn't change the fact that the petition has a huge amount of support.

"If he was here today he would see the EU's announcement as a great cause for celebration. It's a tragedy that he sadly isn't with us.

"If imperial measurements ever die away in this country, they should do so organically - not by threat and compulsion.

"It's a tragedy that he's not here today, but now the campaign still has to be brought to its natural conclusion - a full pardon."