As five "metric martyrs" lose their High Court appeal, former chancellor Lord Howe has called on the government to press ahead with the full implementation of the metric measurements system.

The five market traders lost their legal battle for the right to sell their goods in pounds and ounces, prompting supporters to warn of the "death of democracy".

Neil Herron, spokesman for the traders, said the ruling meant that an act of parliament could be overturned by a Brussels directive, threatening a "deep constitutional crisis".And as the judges ruled that the new regulations were not outside the government's powers, Lord Howe called on the government to press ahead with a full conversion to the metric system.

He suggested that the "metric martyrs" row had developed because metrication had not been "done properly".

"I feel deeply sorry for the metric martyrs because there have been no metric martyrs in other countries that have had full metrication. There was never a shilling or pence martyr, because that conversion was done properly," he told ePolitix.com.

And in a forthright condemnation of the UK's failure to convert to kilos, litres and metres, Lord Howe says it is a "national disgrace" that Britain still operates on the old imperial measurements.

"It truly is a national disgrace to live in this twilight world," he told this website. "Educate children in one way but then have different measurements in shops and on signposts. It's an illustration of the way in which our country hasn't really acquired a familiarity with today's real world."

He said the current situation was highly confusing and calls on the government to have the "courage" of its convictions and force business and the public to scrap a misguided loyalty to miles, feet, pounds and ounces.

"We politicians I'm afraid have let the public down and it's time we summoned up the courage together from all parties, to say enough is enough," he said.

The former chancellor and patron of the UK metric association is calling for leaders of industry and the academic world to join his campaign.

"We need to act collectively and courageously and get together a campaign to finish the job. Going properly metric won't bring the roof down on out heads. It will open up a new era of easier counting and measuring for Britons, with many other benefits for us all," he said.